which bring software engineers (broadly t e r m e d to include expert s y s t e m developers) in c o n t a c t w i t h students of those other disciplines. While the c o m p u t e r science s t u - dents refine their k n o w l e d g e about particular issues in c o m p u t e r science, they also reap the benefits of exposure to other fields such as, psyschology, sociology, or any of the humanitits. They will extend their rational capabilities and will have increased s y m p a t h y for o t h e r fields of study. Likewise, the students of the d o m a i n field w i l l i m p r o v e their c o m m a n d of that study, and at the same t i m e they gain appreciation of c o m p u t e r science. Learning i n t e n - sifies. In Socrates, even the expert claimed to have benefited through the conflicts that she found in DSM-III. CITATIONS Bobrow, Daniel G., Sanjay Mittal, and Mark J. Stefik. Expert Systems: Perils and Promise," in C o m m u n i c a t i o n s of th_e ACM. V o l u m e 29,9 (September, 1986.) Buchanan, Bruce G., David Barstow, Robert Bechtal, et al "constructing an Expert System," in Building. E_~P_~ S_ystems. Hayes-Roth, Waterman, Lenat eds. Reading, Mass: Wesley Publishing Company, Inc. (1983) 127-67. Diag.nostic and Statistical Manual of Mental Disorders, Third Edition. Washington, DC: A m e r i c a n Psychiatric As- sociation, (1980). Fairley, Richard. S o f t w a r e Enci~._eerin_9 Concepts. New York: M c G r a w - H i l l Book Company, (1985). Fellers, Jack W. "Key I-actors in Knowledge Acquisition," in C o m p u t e r Personnel. A quarterly p u b l i c a - tion of the Special Interest Group on C o m p u t e r Personnel Research: ACM Press. Volume II, 1 (May, 1987). Frank, Edwina D., Phd.D., Professor of Psychology, Loyola University, New Orleans, LA: i n f o r m a l interviews and p r o j e c t reviews. (January, 1987 - - August, 1987) Harmon, Paul, and David King. Expert Systems: A r t i f i - cial Intelligence in Business. New York: John Wiley & Sons. (1985). Hayes-Roth, Frederick, Donald A. Waterman, and Douglas B. Lenat. "An O v e r v i e w of Expert Systems," in Building Expe~ Systems. Hayes-Roth, Waterman, Lenat eds. Reading, Mass: Wesley Publishing Company, Inc. (1983) 3-29. Page-Jones, Meilir. The Practical Guide to Structured Systems Desi.gLn ~. E n g l e w o o d Cliffs, N J: Y o u r d o n Press. (1980). Sagalowicz, Daniel. Quoted by Edith Meyers in "Expert Systems: Not for Everyone," in Datamation. (May 15, 1987). Welburn, T y l e r Advanced Structured Cobol: Batch, O n - l i n e , and Data-Base Concepts. Palo Alto, CA: Mayfield Publishing Company, 1983. Zuckerman, Edward, Ph.D., Professor of Psychology, Wellness Resource Center, University of Pittsburg. Pit- tsburg, PA: c o r r e s p o n d e n c e and t e l e p h o n e interviews. (January 1987). AN EXPERT SYSTEM FOR AN I D I O S Y N C R A T I C D O M A I N : LOVE, I N T I M A C Y , A N D FRIENDSHIP J o s e p h S. Fulda Hofstra University (C) 1987 Joseph S. Fulda Expert systems conceived and d e v e l o p e d thus far have dealt with p r o b l e m s , such as medical diagnosis, c i r - cuit design, and mineral exploration, which have o b j e c t i v e solutions. Humans, h o w e v e r , are also experts in reasoning about domains where the key concepts are not o b j e c t i v e l y fixed. We do f o r m subjective, but sound, j u d g m e n t s about i d i o s y n c r a t i c - - i . e . , p e r s o n - s p e c i f i c - - domains. One such d o m a i n is that of love, intimacy, and friendship. Despite the fact that our n o t i o n s of love, intimacy, and friendship vary greatly and that these relationships have been the subject of poets, novelists, biographers, p s y c h o l o g i s t s , and o t h e r students of human nature for centuries, there is enough of a c o m m o n consensus to make c o m m u n i c a t i o n and, very frequently, c o m m o n j u d g m e n t s a b o u t this d o m a i n possible. We present a r u l e - b a s e d expert system, c u r r e n t l y b e - ing i m p l e m e n t e d in PROLOG, which provides a general m e c h a n i s m for handling idiosyncratic domains. Our s y s - t e m also provides a t h o r o u g h example of h o w the a t t a i n - m e n t of c o g n i t i v e - a f f e c t i v e states and resulting r e l a t i o n - ships between people can be m o d e l l e d using a r u l e - b a s e d system. Thus this w o r k should interest c o g n i t i v e s c i e n - tists as well as c o m p u t e r scientists seeking t o e n d o w c o m p u t e r s with truly h u m a n - l i k e thought. The key to our design is, as m i g h t be expected, t o a b s t r a c t out w h a t e v e r is c o m m o n to m o s t people's u n d e r - standing of the nature of a particular class of r e l a t i o n - ships. Nevertheless, there will be a substantial failure rate if idiosyncratic criteria f o r the a t t a i n m e n t or b l o c k i n g of relationships are s i m p l y ignored. Therefore, w e a d o p t the f o l l o w i n g f o r m a l i s m : Iff X (a) Y (b) Then Z (c). This b i d i r e c t i o n a l rule is t o be u n d e r s t o o d as f o l l o w s : If X & Y then Z with p r o b a b i l i t y c; If Z then X w i t h p r o b a b i l i t y a; If Z then Y w i t h p r o b a b i l i t y b. (Of course, " I f Z then X" is identical to "Only if X then Z.") Thus a, b, and c are w h a t have been called c e r t a i n t y factors or, m o r e gracefully, a t - t e n u a t i o n factors (1). (Note that we are nod. associating certainty factors with the a n t e c e d e n t c o n d i t i o n s of the rules in either direction, t h o u g h it is trivial to add these.) The c o n c e p t of a t t e n u a t i o n factors was d e v e l o p e d f o r the MYCIN system, a r u l e - b a s e d expert system f o r m e d i c a l diagnosis (2). This f o r m a l i s m using b i d i r e c t i o n a l rules w i t h attenuation factors o e r a t i v e in both d i r e c t i o n s (cf. 3, 4) neatly handles the p r o b l e m s inherent in reasoning about an idiosyncratic domain. These are t w o : s o m e s o n e may have idiosyncratic r e q u i r e m e n t s for the a t t a i n m e n t or SIGART N e w s l e t t e r , July 1988, N u m b e r 105 Page 30 b l o c k i n g of r e l a t i o n s h i p Z or he m a y i d i o s y n c r a t i c a l l y i g - n o r e s o m e of t h e e l e m e n t s that m o s t do use in d e c i d i n g w h e t h e r to e n t e r r e l a t i o n s h i p Z. Thus, in the e x a m p l e above, if c is .7 this m e a n s that 30% of t h e i n s t a n c e s w h e r e X and ¥, n e v e r t h e l e s s n o t Z b e c a u s e of i d i o s y n c r a t i c r e q u i r e m e n t s f o r t h e a t t a i n m e n t or b l o c k i n g or t h e r e l a t i o n s h i p . Likewise, if a is .8, then in 20% of t h e i n s t a n c e s w h e r e the p a r t i e s have r e l a t i o n s h i p Z, t h e y do so d e s p i t e t h e p r e v a l e n t v i e w t h a t X o u g h t to h o l d f o r Z t o o b t a i n but d o e s no__t. We deal here, i n t e n t i o n a l l y , w i t h a small n u m b e r of rules and r e l a t i o n s h i p s ; nuances of t h e s e are n o t t r e a t e d , since t h e y are far t o o i d i o s y n c r a t i c f o r g e n e r a l a g r e e m e n t , e v e n b r o a d l y c o n s i d e r e d . The r e l a t i o n s h i p s c o n s i d e r e d are, in o r d e r of i n c r e a s i n g c o m m i t m e n t and initial intensity, c o m p a n i o n s h i p , f r i e n d s h i p , confidant(e)s, i n t i m a c y , love, m a r r i a g e , and f a m i l y . Before p r e s e n t i n g t h e rules t h e m s e l v e s , w h i c h are the u l t i m a t e t e s t of t h e m e r i t of the idea, s o m e p e r f a t o r y r e m a r k s on t h e s y s t e m as a w h o l e are in order. First, we have d e s i g n e d the s y s t e m with t w o p u r p o s e s in mind: ease of i m p l e m e n t a t i o n and t e s t i n g and n a t u r a l - ness of r e p r e s e n t a t i o n , w i t h the latter easily t h e m o r e i m - p o r t a n t d e s i d e r a t u m . Thus, e x c e p t f o r c o m p a n i o n s h i p , each level of i n t e r p e r s o n a l c l o s e n e s s i n c l u d e s and s u b - s u m e s t h e p r e v i o u s (and t h e r e f o r e all prior) level(s). Thus if X and Y have a f a m i l y t o g e t h e r , t h e y are m a r r i e d , t h e y l o v e each other, t h e y are intimates, t h e y are c o n f i d a n t s , and t h e y are f r i e n d s ( s u b j e c t t o t h e usual i d i o s y n c r a t i c e x c e p t i o n s ) . This s e e m s natural e n o u g h f o r t h e a t t a i n m e n t of r e l a t i o n s h i p s . H o w e v e r , r e l a t i o n s h i p s are d y n a m i c and w h e n t h e y d e g r a d e , as t h e y so often do, t h e y do n o t do so n i c e l y and m o n o t o n i c a l l y . So w h i l e it m a y be t r u e t h a t a p a r t f r o m t h e i d i o s y n c r a t i c e x c e p t i o n f r i e n d s h i p a l w a y s p r e c e d e s m a r r i a g e , after m a n y years it is c e r t a i n l y p o s s i b l e f o r X and Y to l o v e each o t h e r and miss each o t h e r w h e n apart; b u t n o t t o like each o t h e r or t a k e any p l e a s u r e in each other's c o m p a n y : An'~odd, but c o m m o n , s t a t e of a f - fairs. So t h e s y s t e m p r e s e n t e d here s h o u l d be see e i t h e r as a r e l a t i o n s h i p - a t t a i n m e n t model or as an ideal. Second, t h e s p e c i f i c a t t e n u a t i o n f a c t o r s s e l e c t e d w e r e n o t o b t a i n e d by e m p i r i c a l research. T h e y are s i m p l y l e f t - brain e s t i m a t e s of f r e q u e n c y or r i g h t - b r a i n e s t i m a t e s of p r o b a b i l i t y . T h e y d o seem to c o n f o r m to our ( l i m i t e d ) e x - p e r i e n c e and o u r i n t u i t i o n , b u t a m e t h o d o l o g i c a l c o g n i t i v e s c i e n t i s t m i g h t wish to use o t h e r n u m b e r s , m o r e r i g o r o u s l y o b t a i n e d . T a n t mieux. Since w e are, a f t e r all, d e a l i n g w i t h and p r e s e n t i n g a m e t h o d o l o g y f o r i d i o s y n c r a t i c d o m a i n s , t h e author's o w n p e r s o n - s p e c i f i c b i a s e s or i n s i g h t s m a y o c c a s i o n a l l y be visible. COMPANIONSHIP. Iff X and Y: like e a c h o t h e r 7 (.7) X and Y: w i l l i n g to share t i m e w i t h each o t h e r (1) X and Y: l o n e l y (.8) Then X and Y: c o m p a n i o n s (.5) In t h e f o r w a r d d i r e c t i o n , t h e r e are t h r e e a n t e c e d e n t c o n d i t i o n s w h i c h are r e p r e s e n t a t i v e of t h e t h r e e c l a s s e s of c o n d i t i o n s on w h i c h r e l a t i o n s h i p s m a y be c o n t i n g e n t . First, t h e r e is t h e " e n g i n e , " t h e e m o t i o n a l i m p e t u s f o r t h e r e l a t i o n s h i p , here loneliness. S e c o n d , t h e r e is t h e d e f i n i n g c o n d i t i o n , a c o n d i t i o n w h i c h h o l d s u n i v e r s a l l v w h e n t h e r e l a t i o n s h i p exists, here " w i l l i n g t o share free t i m e w i t h each o t h e r . " Third, t h e r e is a p r e c o n d i t i o n , here s i m p l e a f - f e c t i o n , w i t h o u t w h i c h t h e r e l a t i o n s h i p is b l o c k e d (5), To t h e c o m p u t e r s c i e n t i s t i n t e r e s t e d in t h e f o r m a l i s m i n t r o d u c e d and t h e f r a m e w o r k p r o v i d e d for i d i o s y n c r a t i c d o m a i n s , t h e r e is no d i s t i n c t i o n of i m p o r t a n c e b e t w e e n t h e s e t h r e e classes of c o n d i t i o n s . To the c o g n i t i v e s c i e n - tist, t h e s p e c i a l i s t i m p a r t i n g his k n o w l e d g e to t h e e × p e r t s y s t e m and the k n o w l e d g e e n g i n e e r a s s i s t i n g him, t h e user a p p l y i n g t h e e x p e r t s y s t e m , and t h e g e n e r a l reader, on t h e o t h e r hand, t h e s e d i s t i n c t i o n s are p r e g n a n t w=th m e a n i n g . In p r e s e n t i n g t h e rules, t h e r e f o r e , we shall c o n - t i n u e t o d r a w them. A rule m u s t have o n e or m o r e engines, f o r t h e r e is no r e l a t i o n s h i p w h i c h b e g i n s w i t h no e m o t i o n a l i m p e t u s of any sort; usually, but as we shall see n o t a l w a y s , t h e r e is j u s t one. When t h e a t t e n u a t i o n f a c t o r s of the e n g i n e c o n - d i t i o n s sum t o less t h a n one, as is t h e case here, w i t h c o m p a n i o n s h i p , it is an i n d i c a t i o n t h a t t h e e m o t i o n a l i m - p e t u s f o r t h e r e l a t i o n s h i p class is s o m e t i m e s i d i o s y n c r a t i c . A rule m a y or m a y n o t have a d e f i n i n g c o n d i t i o n , b u t if it has m o r e than one, it is an i n d i c a t i o n of s l o p p y d e s i g n - - in particular, f a i l u r e to g e n e r a l i z e . N o t e t h a t a d e f i n i n g c o n d i t i o n d o e s n o t g u a r a n t e e a r e l a t i o n s h i p (as here), a l t h o u g h the r e l a t i o n s h i p g u a r a n t e e s it. As w e shall see, h o w e v e r , m o s t a n t e c e d e n t c o n d i t i o n s are p r e c o n - ditions. The l o w a t t e n u a t i o n f a c t o r f o r c o m p a n i o n s h i p r e f l e c t s t h e f a c t that, unlike m o r e c o m m i t t e d r e l a t i o n s h i p s , it a r i s e s f r o m a g e n e r a l i z e d l o n e l i n e s s on t h e part of, t o use t h e s y s t e m ' s names, X and Y, and m a n y o t h e r r a n d o m or i d i o s y n c r a t i c f a c t o r s h e l p d e c i d e w h e t h e r t h e t w o w i l l b e - c o m e c o m p a n i o n s . As w e a s c e n d the h i e r a r c h y of r e l a t i o n s h i p s , r a n d o m i n f l u e n c e s w i l l b e c o m e i n c r e a s i n g l y n e g l i g i b l e and i d i o s y n c r a t i c f a c t o r s i n c r e a s i n g l y v i s i b l e . FRIENDSHIP. Iff X and Y: like each o t h e r 2 (.8) X and Y: r e s p e c t each other. (.7) X and Y: w a n t to share free t i m e w i t h each o t h e r (1) T h e n X and Y: f r i e n d s ( 9 ) For f r i e n d s h i p , w a n t i n g t o share free t i m e w i t h each o t h e r is b o t h t h e e n g i n e and t h e d e f i n i n g c o n d i t i o n . Note t h a t the p r e c o n d i t i o n s are still n e c e s s a r y t o e n s u r e that t h e m o t i v a t i o n f o r w a n t i n g each o t h e r ' s c o m p a n y is f r i e n d s h i p and n o t (say) business. T h o s e w h o a t t a i n the c o g n i t i v e - a f f e c t i v e state c o m m o n t o friends w i t h o u t liking or r e s p e c t i n g each o t h e r are, of course, a c c o u n t e d f o r by t h e a t t e n u a t i o n factors. For s o m e people, all i m p o r t a n t b u s i n e s s a s s o c i a t e s m a y be friends. M a n y w i l l find t h e p r e c o n d i t i o n s g i v e n here i n a d e - q u a t e ; t h e i r n o t i o n of f r i e n d s h i p is p r o b a b l y akin t o o u r n o t i o n of c o n f i d a n t s , w h i c h will be p r e s e n t e d n e x t and a m o u n t s t o classical, t r u e f r i e n d s h i p ( " f r i e n d s h i p w i t h a c a p i t a l 'F'"). As t h e w o r d is n o r m a l l y used t o d a y , h o w e v e r , " f r i e n d " m e a n s (at most) w h a t is g i v e n above. N o t i c e t h e d i f f e r e n c e b e t w e e n the d e f i n i n g c o n d i t i o n s f o r c o m p a n i o n s h i p and f r i e n d s h i p : " w i l l i n g " vs. " w a n t " to 1A rule elaborating this will be presented later. 2A rule elaboratin 9 this will be presented later. SIGART N e w s l e t t e r , J u l y 1988, N u m b e r 105 Page 31 s h a r e f r e e t i m e w i t h e a c h o t h e r . A p e r s o n - s p e c i f i c n e e d has r e p l a c e d a g e n e r a l i z e d l o n e l i n e s s . CONFIDANTS. Iff X and Y: f r i e n d s (.85) X and Y: r e s p e c t e a c h o t h e r h i g h l y (.7) X and Y: w i l l i n g / w a n t t o s h a r e t h e i r t h o u g h t s and f e e l i n g s w i t h e a c h o t h e r (1) X and Y: m i s s e a c h o t h e r w h e n a p a r t (.5) X and Y: t r u s t e a c h o t h e r 3 (.8) T h e n X and Y: c o n f i d a n t ( e ) s (.7) O n c e a g a i n , t h e e n g i n e and t h e d e f i n i n g c o n d i t i o n are t h e s a m e : s h a r i n g t h o u g h t s and f e e l i n g s . This is f r i e n d s h i p o n a m o r e i n t i m a t e l e v e l (it s u b s u m e s f r i e n d s h i p w i t h i d i o s y n c r a t i c e x c e p t i o n s ) t h a n s h a r i n g t i m e a l o n e can e v e n reach. It is a l s o t h e l o w e s t l e v e l o f t h e h i e r a r c h y of t h e r e l a t i o n s h i p c l a s s e s w e c o n s i d e r at w h i c h m i s s i n g e a c h o t h e r , a c o g n i t i v e - a f f e c t i v e s t a t e c e n t r a l t o s t r o n g r e l a t i o n s h i p s , c o m e s i n t o play. For s o m e , it is a p r e c o n - d i t i o n t o b e i n g a c o n f i d a n t (or a v e r y q u i c k r e s u l t ) ; f o r s o m e , it m a y a l s o be an e n g i n e c o n d i t i o n . O n e m i g h t s u p p o s e t h a t " t r u s t i n g e a c h o t h e r " and b e i n g " w i l l i n g t o s h a r e t h e i r t h o u g h t s and f e e l i n g s w i t h e a c h o t h e r " w o u l d be c o i n c i d e n t . E x p e r i e n c e t e a c h e s t h a t t h i s is n o t a l w a y s so, as t h e n e e d t o c o n f i d e , in m a n y so o f t e n o v e r p o w e r s d o u b t s a b o u t t h e o t h e r ' s t r u s t w o r t h i n e s s . It is a l s o a r e f l e c t i o n o f t h e m e c h a n i s m o f t r u s t b u i l d u p , w h i c h is n o t u n l i k e t h e b u i l d u p o f b a n d c r e d i t . O n e t r u s t s a l i t t l e ; if it w o r k s out, o n e t r u s t s a l i t t l e m o r e . Of c o u r s e , h o w e v e r n a t u r a l t h i s s y s t e m m a y be and h o w e v e r p r e v a l e n t , it l e a v e s t h e c o n f i d a n t ( o r bank) o p e n t o d i s a s t e r in u n f o r - t u n a t e i n s t a n c e s . P e r h a p s t h a t ' s w h y a n o t h e r m e t h o d - - f o r m a l a n d i n f o r m a l r e f e r e n c e s - - h a s e v o l v e d f o r t h e r e s o l u t i o n o f t h e t r u s t i s s u e (by p o t e n t i a l c r e d i t o r s and p o t e n t i a l f r i e n d s alike). INTIMATES. Iff X and Y: c o n f i d a n t s ( e ) s (.95) X a n d Y: k n o w e a c h o t h e r f o r s o m e t i m e (.5) X a n d Y: e m o t i o n a l l y c o m p a t i b l e e v e n in c l o s e q u a r t e r s (.5) X a n d Y: find e a c h o t h e r a t t r a c t i v e (.8) T h e n X and Y: i n t i m a t e s (.5) I n t i m a c y , as w e are c o n s i d e r i n g it, is a s e r i o u s r e l a t i o n s h i p o n e s t e p shy o f r o m a n t i c l o v e , n o t m e r e p h y s i c a l i n t i m a c y w i t h o u t a v e r y p o w e r f u l e m o t i o n a l c o m - p o n e n t . O b v i o u s l y , m e r e p h y s i c a l i n t i m a c y is p o s s i b l e w h e n X and Y are s t r a n g e r s , h a r d l y i n t i m a t e s as w e are u s i n g t h e t e r m . T h e i n t i m a c y t o w h i c h w e r e f e r is a s t a t e o f h e a r t and m i n d , a c o g n i t i v e - a f f e c t i v e s t a t e , j o i n e d t o a s t a t e o f a f f a i r s (in t h e p h i l o s o p h e r ' s s e n s e o f t h e p h r a s e ) w h i c h can be r e a c h e d w i t h o u t a c o n f i d a n t - t y p e r e l a t i o n - ship i d i o s y n c r a t i c a l l y o n l y o n e t i m e in t w e n t y . For the f o r w a r d - c h a i n i n g a n t e c e d e n t "X and Y: p h y s i c a l l y i n t i m a t e " t h e c o n s e q u e n t s w o u l d h a v e v e r y d i f f e r e n t a t t e n u a t i o n f a c t o r s , say, .05, .25, .02, .6, r e s p e c t i v e l y . A n o t h e r i s s u e t h a t m u s t e v e n t u a l l y be a d d r e s s e d h e r e is t h a t o f s a m e - s e x r e l a t i o n s h i p s . For h e t e r o s e x u a l s , t h e f o u r t h a n t e c e d e n t c o n d i t i o n r u l e s o u t s a m e - s e x r e l a t i o n - ships. For o t h e r s , it d o e s not, n o r d o e s a n y t h i n g e l s e in t h e rule. S t u d i e s s h o w t h a t o n e - o n e r e l a t i o n s h i p s are m u c h m o r e c o m m o n a m o n g h e t e r o s e x u a l s , b u t it is n o t t o be s u p p o s e d t h a t t h i s c r e a t e s a s e r i o u s o v e r s t a t e m e n t o f t h e c h a n c e s o f an i n t i m a t e r e l a t i o n s h i p d e v e l o p i n g (50%) g i v e n all t h e s t a t e d a n t e c e d e n t c o n d i t i o n s . H a v i n g d e a l t w i t h t h e s e t w o s i d e i s s u e s , w e r e t u r n t o an e x p o s i t i o n o f t h e rule. The e n g i n e h e r e is m u t u a l a t - t r a c t i o n and as a n y o n e w i l l a d m i t u n d e r p e r s i s t e n t q u e s - t i o n i n g it is n o t a s u r e t h i n g ; t e c h n i c a l l y , t h a t is, it d o e s n o t g i v e "X and Y: i n t i m a t e s " an a t t e n u a t i o n f a c t o r o f 1. W h a t w i l l m a k e t w o p e o p l e d e c i d e t o u p g r a d e a c o n f i d a n t r e l a t i o n s h i p t o an i n t i m a t e r e l a t i o n s h i p is h i g h l y i d i o s y n c r a t i c , so m u c h so t h a t f u l l y h a l f t h e t i m e t h a t t h e a n t e c e d e n t s are t r u e , i n t i m a c y w i l l n e v e r t h e l e s s n o t r e s u l t . If it s e e m s t o t h e r e a d e r t h a t t h i s is s u r e l y a g r o s s e x - a g g e r a t i o n , it is l i k e l y t h a t he is u n w i t t i n g l y u s i n g i n t i m a c y in a w e a k e r s e n s e b y n o t b e i n g s e n s i b l e o f t h e f u l l r a n g e o f a n t e c e d e n t c o n d i t i o n s f o r a c o n f i d a n t - t y p e r e l a t i o n s h i p , w h i c h r e l a t i o n s h i p is, in all b u t a h a n d f u l o f i d i o s y n c r a t i c cases, p r e r e q u i s i t e t o i n t i m a c y as h e r e d e f i n e d . (And t h e r e a r e of c o u r s e t h e r e q u i r e m e n t s o f t h e e n g i n e c o n d i t i o n and t h e t w o p r e c o n d i t i o n s . ) R O M A N T I C LOVE, Iff X and Y: i n t i m a t e s (.95) X and Y: w i l l i n g / w a n t m u t u a l e m o t i o n a l c o m m i t m e n t ( . 7 5 ) X and Y: w i l l i n g / w a n t a b s o r p t i o n in e a c h o t h e r ' s life(.7) X and Y: m i s s e a c h o t h e r q u i t e i n t e n s e l y w h e n a p a r t (1) T h e n X and Y: l o v e e a c h o t h e r ( r o m a n t i c a l l y ) (.9) The e n g i n e s h e r e are t h e m u t u a l d e s i r e f o r e m o t i o n a l c o m m i t m e n t , o n e - o n e l o y a l t y , a n d t h e m u t u a l d e s i r e f o r t o t a l i n v o l v e m e n t in e a c h o t h e r ' s life ( i n v o l v e m e n t d o e s n o t m e a n d o m i n a t i o n , u n w a n t e d i n t e r f e r e n c e , etc.) and t h e d e f i n i n g c o n d i t i o n f o r t h i s c o g n i t i v e - a f f e c t i v e s t a t e is g i v e n b y t h e f i n a l a n t e c e d e n t c o n d i t i o n . It w i l l be i s t r u c - t i r e t o c o m p a r e l o v i n g and l i k i n g ( t h e l a t t e r is r e q u i r e d f o r c o m p a i o n s h i p and f r i e n d s h i p (and, as e x p l a i n e d e a r l y in t h i s paper, b y i n c l u s i o n in all m o r e i n t e n s e r e l a t i o n s h i p s ) ) : Iff X and Y: e n j o y e a c h o t h e r ' s c o m p a n y (.95) X and Y: e m o t i o n a l l y c o m p a t i b l e (.8) T h e n X and Y: like e a c h o t h e r (1) T h u s t h e e m p h a s i s in l o v i n g is on a l o n g i n g w h e n a p a r t , w h i l e t h e e m p h a s i s in l i k i n g is o n an a g r e e a b l e n e s s w h e n t o g e t h e r . Of c o u r s e , e x c e p t f o r i d i o s y n c r a t i c c a s e s , l o v e i n c l u d e s i n t i m a c y w h i c h i n c l u d e s . . . . f r i e n d s h i p a n d , t h e r e f o r e , l i k i n g . N e v e r t h e l e s s , t h i s n e g a t i v e e m p h a s i s h e l p s e x p l a i n w h y l o v e w i t h o u t a f f e c t i o n as m a y o c c u r w h e n a r e l a t i o n s h i p d e g r a d e s can b e a c l e a r l y d e s t r u c t i v e f o r c e and w h y l e c t u r e s e n t i t l e d " H o w t o Fall o u t o f L o v e " d r a w l a r g e a u d i e n c e s . MARIAGE. Iff X and Y: l o v e e a c h o t h e r (.65) X and Y: c u l t u r a l l y c o m p a t i b l e (.7) X and Y: k n o w e a c h o t h e r f o r a c o n s i d e r a b l e t i m e (.75) X and Y: w i l l i n g / w a n t m u t u a l i n s t r u m e n t a l c o m m i t m e n t X and Y: f i n d e a c h o t h e r ' s i d i o s y n c r a t i c b e h a v i o r s t o l e r a b l e t o p l e a s i n g (.5) X and Y: l o n e l y ( . 7 ) / X a n d Y: w a n t kids (.9) T h e n X and Y: m a r r i e d ( . 7 ) / X and Y: m a r r i e d (.75) 3A rule elaboratm 9 this will be presented later. SIGART N e w s l e t t e r , July 1988, N u m b e r 105 Page 32 M a r r i a g e c o n d i t i o n s are f a i r l y i d i o s y n c r a t i c ; h e n c e o n l y 7 0 - 7 5 % of t h e t i m e t h a t t h e a n t e c e d e n t c o n d i t i o n s are s a t i s f i e d is t h e c o n s e q u e n t r e a l i z e d . S i n c e n o c o n d i t i o n as t o g e n d e r is i m p o s e d , if a s a m e - s e x r e l a t i o n s h i p m e e t s all t h e a n t e c e d e n t c o n d i t i o n s , it is a m o n g t h e 3 0 % ( f o r g e t a b o u t w a n t i n g kids as an a n t e c e d e n t ! ) o f s u c h c a s e s w h e r e t h e r u l e is i d i o s y n c r a t i c a l l y n o t t r i g g e r e d . A l s o l o w a r e t h e a t t e n u a t i o n f a c t o r s in t h e o t h e r d i r e c t i o n . This m a y i n d i c a t e w h y so m a n y m a r r i a g e s s o u r . In o t h e r w o r d s , if t h e c o n s e q u e n t w e r e "X and Y: h a p p i l y m a r r i e d " t h e a t t e n u a t i o n f a c t o r s w o u l d be f a r h i g h e r , p e r h a p s .98, .95, .8, .7, .9, .7/.9 r e s p e c t i v e l y . T h e r e are t w o o r p o s s i b l y t h r e e e n g i n e s h e r e w h i c h o v e r l a p ; w a n t i n g i n s t r u m e n t a l c o m m i t m e n t , w a n t i n g kids, a n d b e i n g l o n e l y . As t h e a t t e n u a t i o n f a c t o r s f o r m a r r i a g e s h o w , w a n t i n g kids is a s t r o n g e r s p u r t o m a r r i a g e t h a n l o n e l i n e s s , w h i c h can m o r e e a s i l y be s a t i s f i e d b y m e a n s s h o r t of m a r r i a g e . As i m p l e m e n t e d , t h e r u l e s f o r m a r r i a g e in t h e s y s t e m n u m b e r t h r e e . One w i t h "X and Y: w a n t kids (.9)" l e a d i n g t o "X and Y: " m a r r i e d (.75)"; o n e w i t h "X and Y: l o n e l y (.7)" l e a d i n g t o "X and Y: m a r r i e d (.7)"; a n d o n e w i t h b o t h "X and Y: l o n e l y (.7)" and "X a n d Y: w a n t kids (.9)" l e a d i n g t o "X and Y: m a r r i e d (.75)." T h e r e is no r e d u n d a n c y in t h e p r e s e n c e o f t h e t h i r d r u l e , s i n c e all r u l e s are b i d i r e c t i o n a l . F u r t h e r m o r e , t h a t t w o r u l e s say t h a t 75% o f c o u p l e s w i l l e n d up m a r r i e d d o e s n o t g u a r a n t e e t h a t t h e y w i l l be t h e s a m e 75%, so f r o m an i n - t e l l e c t u a l p o i n t of v i e w , it is w e l l t o i n c l u d e it, e v e n if it m a k e s no d i f f e r e n t p r o b a b i l i s t i c p r e d i c t i o n . T h e r e are t h r e e d e g r e e s o f e m o t i o n a l c o m p a t i b i l i t y r e q u i r e d by t h e s y s t e m : f i n d i n g e a c h o t h e r ' s i d i o s y n c r a t i c b e h a v i o r s t o l e r a b l e t o p l e a s i n g - - f o r m a r r i a g e , e m o t i o n a l c o m p a t i b i l i t y e v e n in c l o s e q u a r t e r s - - f o r i n t i m a c y , and (basic) e m o t i o n a l c o m p a t i b i l i t y - - f o r c o m p a n i o n s h i p (via liking). The l e v e l s o f c o m p a t i b i l i t y r e q u i r e d m a y v a r y on a p e r s o n - s p e c i f i c basis and that, o f c o u r s e , is d e a l t w i t h b y t h e a t t e n u a t i o n f a c t o r s . A w o r d a b o u t l o n e l i n e s s , a r e q u i r e m e n t f o r c o m - p a n i o n s h i p and m a r r i a g e - - b u t n o t h i n g in b e t w e e n , is in o r d e r . The s y s t e m r e f l e c t s t h e i d e a t h a t e i t h e r c o m - p a n i o n s h i p w i l l s a t i s f y l o n e l i n e s s o r if it d o e s n o t , n e i t h e r w i l l f r i e n d s h i p , a c o n f i d a n t , o r e v e n i n t i m a c y and l o v e . T h e s e i n - b e t w e e n r e l a t i o n s h i p s s a t i s f y p e r s o n - s p e c i f i c and t y p e - s p e c i f i c (to c o n f i d e , t o be i n t i m a t e , etc.) n e e d s , r a t h e r t h a n l o n e l i n e s s in g e n e r a l . M a r r i a g e , o n t h e o t h e r h a n d , a d d s t o l o v e ( w i t h its s a t i s f a c t i o n o f a w i d e v a r i e t y o f p e r s o n - s p e c i f i c a n d t y p e - s p e c i f i c n e e d s ) c o n s t a n t c o m - p a n i o n s h i p . FAMILY Iff X and Y: m a r r i e d (1) X and Y: w a n t kids (.9) X a n d Y: s u f f i c i e n t m e a n s and s p a c e (.5) T h e n × and Y: h a v e a f a m i l y t o g e t h e r (.95) T h e e n g i n e h e r e , o b v i o u s l y , is w a n t i n g kids. V i r t u a l l y all m a r r i e d c o u p l e s w h o w a n t kids d o h a v e o r a d o p t t h e m . The o n l y s o m e w h a t g e n e r a l c o n s t r a i n t s e e m s t o be s u f - f i c i e n c y o f m e a n s a n d s p a c e and, as t h e a t t e n u a t i o n f a c t o r s h o w s (50% o f f a m i l i e s d o n ' t h a v e s u f f i c i e n t m e a n s and space), it is n o t t e r r i b l y c o n s t r a i n i n g . It is i n s t r u c t i v e t o c o m p a r e t h e f i n a l t h r e e r u l e s o f t h e h i e r a r c h y : f a m i l y g i v e n m a r r i a g e , m a r r i a g e g i v e n l o v e , l o v e g i v e n i n t i m a c y . T h e c o m p a r i s o n s u g g e s t s t h a t t h e c o n - d i t i o n s f o r m a r r i a g e are f a r m o r e i d i o s y n c r a t i c t h a n a r e t h o s e f o r a f a m i l y g i v e n m a r r i a g e a n d l o v e g i v e n i n t i m a c y . P e o p l e w h o a r e m a r r i e d d o a l m o s t a l w a y s h a v e f a m i l i e s ; p e o p l e w h o a r e i n t i m a t e and m e e t t h e r e m a i n i n g c o n - d i t i o n s d o fall in l o v e . But e v e n if l o v e is t r i e d a n d t r u e , m a r r i a g e is o f t e n n o t t h e result. (By o f t e n , w e m e a n , o f c o u r s e , 2 5 - 3 0 % o f t h e t i m e . ) The n o n - i d i o s y n c r a t i c c o n - d i t i o n s f o r m a r r i a g e are a l s o a g o o d d e a l m o r e d e m a n d i n g t h a n t h o s e f o r l o v e g i v e n i n t i m a c y a n d f a m i l y g i v e n m a r - riage. Thus w i t h s u c h a m o d e l o f r e l a t i o n s h i p a t t a i n m e n t , it is n o s u r p r i s e t h a t m a r r i a g e s are h a r d t o m a i n t a i n . T h a t c o n c l u s i o n f o l l o w s f r o m t h e s i n g l e p r e m i s e t h a t t h e h a r d e r a r e l a t i o n s h i p is t o f o r m , t h e e a s i e r it is t o d a m a g e . W h i l e w e c o u l d see an i n t e l l e c t u a l c a s e e i t h e r w a y o n t h e p r e m i s e , e m p i r i c a l e v i d e n c e s u p p o r t s b o t h t h e p r e m i s e and t h e c o n c l u s i o n . T h i s is o n l y o n e o f m a n y d o m a i n - s p e c i f i c c o m m e n t s m a d e in t h i s w o r k . It is n a t u r a l w h e n d e s i g n i n g a s y s t e m t o be an e x p e r t and d i s c u s s i n g o n e ' s i d e a s w i t h c o l l e a g u e s and a s s o c i a t e s t o l e a r n a c o n s i d e r a b l e a m o u n t a b o u t t h e d o m a i n as w e l l as a b o u t e x p e r t s y s t e m d e s i g n f o r i d i o s y n c r a t i c d o m a i n s in g e n e r a l . R e t u r n i n g t o t h e l a t t e r , an a t t e m p t w a s m a d e t h r o u g h o u t t h e s y s t e m t o r e s t r i c t c o n s i d e r a t i o n t o c o n - d i t i o n s w i t h a t t e n u a t i o n f a c t o r s t h a t w o u l d m a k e at l e a s t .5. Thus, in t h e c a s e of t h e f a m i l i a l r e l a t i o n s h i p , t h e 5% o f c o u p l e s w h o d o n ' t h a v e o r a d o p t c h i l d r e n d e s p i t e t h a t desire, t h e i r b e i n g m a r r i e d t o e a c h o t h e r , and t h e i r h a v i n g s u f f i c i e n t m e a n s a n d s p a c e h a v e " r e a s o n s o f t h e i r o w n " - - i d i o s y n c r a t i c o r p e r s o n - s p e c i f i c f a c t o r s w h i c h i n f l u e n c e t h e r e l a t i o n s h i p s t h e y f o r m . L i k e w i s e , t h e 10% o f c o u p l e s w h o h a v e a f a m i l y b u t d o n o t w a n t c h i l d r e n m u s t a l s o h a v e " r e a s o n s o f t h e i r o w n " - - p e r h a p s r e l i g i o u s b e l i e f s o r c o n c e r n w i t h w h a t t h e n e i g h b o r s t h i n k , etc. It is i m p o r t a n t in an e x p e r t s y s t e m d e s i g n e d f o r an i d i o s y n c r a t i c d o m a i n n o t t o t r y t o d i s c o v e r e v e r y i d i o s y n c r a s y and a s s i g n it an a p p r o p r i a t e a t t e n u a t i o n f a c t o r (less t h a n .5), o r t h e s y s t e m w i l l r a p i d l y be t r a n s f o r m e d f r o m o n e w h i c h h a n d l e s i d i o s y n c r a s i e s in its d o m a i n t o o n e w h i c h m e r e l y r e f l e c t s t h e i d i o s y n c r a s i e s o f its a u t h o r . The l a t t e r is t o s o m e e x - t e n t i m p o s s i b l e t o a v o i d in a n y d o m a i n w h e r e t h e k e y c o n c e p t s are n o t o b j e c t i v e l y f i x e d ; w e h o p e w e h a v e d o n e a c r e d i b l e job. REFERENCES 1. W i n s t o n , P.H., A r t i f i c i a l I n t e l l i g e n c e , 1984, R e a d i n g , MA; A d d i s o n W e s l e y . 2. S h o r t l i f f e , E. H. and B u c h a n a n , B.G., "A M o d e l o f I n - e x a c t R e a s o n i n g in M e d i c i n e , " M a t h e m a t i c a l Bio__ s c i e n c e s 23(1975): 3 5 1 - 3 7 9 . 3. D u d a , R.O., et al., " D e v e l o p m e n t o f t h e P r o s p e c t o r C o n s u l t a t i o n S y s t e m f o r M i n e r a l E x p l o r a t i o n , " S e p - t e m b e r 1978, M e n l o Park, CA: SRI. 4. Duda, R.O, e t al., "A C o m p u t e r - B a s e d C o n s u l t a n t f o r M i n e r a l E x p l o r a t i o n , " S e p t e m b e r 1979, M e n l o Park, CA: SRI. 5. V e r e , S.A., " R e l a t i o n a l P r o d u c t i o n S y s t e m s , " A r t i f i c i a l I n t e l l i g e n c e 8(1977): 4 7 - 6 8 . APPENDIX A. DEFAULT RULE. Iff t r u e (1) T h e n X a n d Y: n o t h i n g (.8) T h e s y s t e m ' s u n i v e r s e o f d i s c o u r s e is all c o u p l e s , X and Y, w h o k n o w e a c h o t h e r , h o w e v e r s l i g h t l y . T h i s r u l e s t a t e s t h a t 8 0 % o f s u c h c o u p l e s a r e n e i t h e r c o m p a n i o n s n o r f r i e n d s ( n o r a n y t h i n g c l o s e r ) ; it s e r v e s as a d e f a u l t . B. ADOPTION RULES (UNDIRECTIONAL). 1. If X and Y: m a r r i e d Y a n d Z: f r i e n d s ( o r m o r e ) T h e n X and Z: c o m p a n i o n s (.6) SIGART Newsletter, J u l y 1988, N u m b e r 105 Page 33 2. If X and Y: married Y and Z: c o n f i d a n t s ( m o r e w o u l d p r o b a b l y lead t o d i v o r c e ) Then X and Z: friends (.4) 3. If X and Y: married Y and Z: c o n f i d a n t s Then X and Z: c o m p a n i o n s (.7) There is little p o i n t in w r i t i n g rules f o r × and Y: less than married, since the a t t e n u a t i o n f a c t o r s w o u l d be v e r y l o w ( v e r y f e w such "adoptions"). it is p o s s i b l e t h a t for X and Y: have a f a m i l y t o g e t h e r , the a t t e n u a t i o n factors w o u l d be lower, since p e o p l e with f a m i l i e s have less time. Finally, s u b j e c t to i d i o s y n c r a t i c e x c e p t i o n s , a d o p t i o n s never result in m o r e than a friend or, if t h e y do, t h e y cease b e - ing an a d o p t i o n and m e e t the standard a n t e c e d e n t c o n - ditions. N o t e t h a t the a n t e c e d e n t s of (2) and (3) o v e r l a p as do t h o s e of (1) and (2)/(3) t o s o m e e x t e n t (because, w i t h i d i o s y n c r a t i c e x c e p t i o n s , c o n f i d a n t s are friends). One m i g h t t r y t o r i g o r o u s l y use a v a i l a b l e m e t h o d s (see refs. 2,3,4) to o b t a i n b e t t e r n u m b e r s . But t h e a b o v e w i l l do. C. TRUST RULE. IFF X and Y: believe t h e y can repose t h e i r t h o u g h t s and f e e l i n g s in each o t h e r w i t h o u t facing ridicule, r e j e c t i o n , etc. (.85) X and Y: believe ~hey can repose t h e i r t h o u g h t s and f e e l i n g s in each o t h e r w i t h o u t facing e x p o s u r e l e a d i n g to m t e r p e r s o n a l a n d / o r i n s t r u m e n t a l harm (.85) X and Y: believe t h e y can repose t h e i r t h o u g h t s and f e e l i n g s in each o t h e r w i t h o u t fearing t h a t t h e i r c o n f i d e n c e s will e v e n t u a l l y be used a g a i n s t t h e m e m o t i o n a l l y i.e., t h r o w n up at t h e m , etc. (.7) X and Y: trust each o t h e r (1'.) The difference in a t t e n u a t i o n f a c t o r s r e f l e c t s t h e fact t h a t n e a r l y e v e r y o n e w o u l d s o o n e r risk l o n g - t e r m e m o - t i o n a l hurt ( c o n d i t i o n 3) t h a n s h o r t - t e r m e m o t i o n a l hurt ( c o n d i t i o n 1) or e x p o s u r e ( c o n d i t i o n 2). SELECTED AI-RELATED DISSERTATIONS Assembled by: Susanne M. Humphrey National Library of Medicine Bethesda, M D 2 0 8 9 4 and Bob Krovetz University of Massachusetts Amherst, MA 01002 The f o l l o w i n g are c i t a t i o n s s e l e c t e d by t i t l e and a b s t r a c t as being related t o AI, resulting f r o m a c o m p u t e r search, using the BRS I n f o r m a t i o n T e c h n o l o g i e s r e t r i e v a l service, of t h e Dissertation Abstracts I n t e r n a t i o n a l (DAI) d a t a b a s e produced by U n i v e r s i t y M i c r o f i l m s I n t e r n a t i o n a l . The online file includes abstracts, w h i c h are n o t published in this listing, but t h e c i t a t i o n s b e l o w do include the DAI reference f o r f i n d i n g t h e a b s t r a c t in t h e published DAI. Other e l e m e n t s of the c i t a t i o n are a u t h o r ; u n i v e r s i t y , degree, and, if available, n u m b e r of pages; title; UM o r d e r n u m b e r and y e a r - m o n t h of DAI; and DAI s u b j e c t c a t e g o r y chosen by the a u t h o r of t h e dissertation. References are s o r t e d first by the initial DAI subject c a t e g o r v and second by the author. In a d d i t i o n t h e d a t a b a s e i n c l u d e s m a s t e r s abstracts, d e n o t e d by MAI (Masters A b s t r a c t s I n t e r n a t i o n a l ) instead of DAI as t h e r e f e r e n c e to the a b s t r a c t in t h e published MAI. Unless o t h e r w i s e specified, paper or m i c r o f o r m copies of d i s s e r t a t i o n s m a y be o r d e r e d from U n i v e r s i t y M i c r o f i l m s International, Dissertation Copies, Post Office Box 1764, Ann Arbor, MI 48106; t e l e p h o n e for U.S. ( e x c e p t Michigan, Hawaii, Alaska): 1 - 8 0 0 - 5 2 1 - 3 0 4 2 , f o r Canada: 1 - 8 0 0 - 2 6 8 - 6 0 9 0 . Price lists and o t h e r o r d e r i n g and s h i p - ping i n f o r m a t i o n are in the i n t r o d u c t i o n t o t h e p u b l i s h e d DAI. DIAZ, JULIAN, I I I . Georgia State U n i v e r s i t y - C o l l e g e of Business A d m i n i s t r a t i o n Ph.D 1987, 310 pages. PROCESS TRACING INVESTIGATION INTO PROBLEM- SOLVING WITHIN RESIDENTIAL REAL ESTATE A P - PRAISAL. DAI V48(09), SecA, pp2378. U n i v e r s i t y M i c r o f i l m s Order N u m b e r ADG87-26477. Business A d - m i n i s t r a t i o n , General. MATHIESON, KIERAN DONALDI. Indiana U n i v e r s i t y Ph.D 1987, 159 pages. A MACHINE LEARNING APPROACH TO FLEXIBLE MANUFACTURING SYSTEM SCHEDULING. DAI V48(09), SecA, pp2378. U n i v e r s i t y M i c r o f i l m s Order N u m b e r ADG87-27515. Business A d m i n i s t r a t i o n , General. BOCK, DOUGLAS BRIAN. Indiana U n i v e r s i t y Ph.D 1987, 201 pages. SETTING DUE DATES FOR COMPUTER BASED SYSTEM DEVELOPMENT PROJECTS. DAI V48(09), SecA, pp2384. U n i v e r s i t y M i c r o f i l m s O r d e r N u m b e r ADG87-27484. Business A d m i n i s t r a t i o n , M a n a g e m e n t ABRAMS, DAVID HOWARD. Georgia I n s t i t u t e of T e c h n o l o g y D.B. 1987, 220 pages. A REFERENCE MODEL FOR HETEROGENEOUS DATA BASE MANIPULATION AND AN EXPERT SYSTEM PROTOTYPE FOR HOMOGENEOUS DATA BASE MANIPULATION. DAI V48(09), SecB. U n i v e r s i t y M i c r o f i l m s Order N u m b e r A D G 8 7 - 2 7 1 8 4 . C o m p u t e r Science. S I G A R T N e w s l e t t e r , J u l y 1988, N u m b e r 105 P a g e 34