FOREGROUND AND BACKGROUND INFORMATION IN REASONING

LEO G. M. NOORDMAN

University of Gronin~en

Every meanin~ful message contains new information, or at least information meant by the speaker to be new for the hearer, embedded in old information. Every messa~e aims at communicating something new. If I were to say now two and two is four, that would be meanin~less, because that sentence contains only old information and nothing new is communicated. On the other hand, a sen­tence that contains only new information e.g. suddenly he got extremely scared cannot be understood, it cannot be assimilated to previous knowledge. The quite normal sentence I met your brother yesterday contains as new information that a certain meeting has taken place at a certain moment. There is also old information: know­ledge shared by the speaker and hearer which is presup­posed to be true. The presupposed information in this case is that the hearer has a brother. A linguist who has recently studied verbal communication and semantics in the framework of old and new information is Chafe (1970, 1972). Related distinctions are topic and com­ment, ~iven and new, theme and rheme (Halliday, 1967, 1970) presupposition and focus (Chomsky, 1971).

The psycholo~ical implications of new and old informa­tion have especially been studied by Clark (1973; Clark and Haviland, 1976). He has developed a theory about communication and comprehension in terms of the ~iven­new contract elaborating upon Grice's cooperative princi­ple (1967). According to Clark, the speaker is coopera­tive if he communicates information he thinks the lis­tener already knows as given information and information

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290 L.G.M. NOORDMAN

he thinks the listener doesn't yet know as new infor­mation. He can do this by using a certain syntactic construction or a certain stress pattern. The listener divides incoming information into given and new infor­mation, he then searches memory for a unique antecedent that matches the given information; the new information is integrated into memory by attaching it to that unique antecedent.

Related to the notions of given and new information are the notions of presupposition and assertion. The assertion of a sentence is the information that is explicitly communicated; a presupposition is what is assumed to be true by the speaker and hearer. The stan­dard test for the claim that a certain proposition is a presupposition of a sentence is to see whether it is preserved under negation (Fraser, 1972; Horn, 1969; Lakoff, 1971). The negation in the sentence I did not meet your brother yesterday does not affect the old infor­mation that you have a brother. This notion of presup­psotion is called logical presupposition. The notion of presupposition is sometimes defined with respect to the beliefs of the hearer and the speaker. A proposition is considered as a presupposition of a sentence, if it is not affected by the negation of the sentence as it is understood by the hearer and the speaker. It is in this way that Miller (1969) uses the notion of presuppo­sition. His discussion is based on the implications of a negation in a predicate nominal sentence, e.g. Leslie is not a mother. It is an empirical question to deter­mine the implications of a negation, as Miller says. He suggests that the sentence X is not a mother implies that X is a woman and denies that X is a parent; woman then is the presupposition of mother, because it is not affected by the negation; parent, which is negated with respect to X, is the assertion.

It should be clear that this notion of presupposition differs from the notion of logical presupposition given above. The sentence Leslie is not a mother but a father is not meaningless as 1s the sentence I met your brother yesterday but you don't have a brother. The sentence Leslie is not a mother does not logically exclude the possibility that Leslie is a man. What is claimed however, is that the speaker and the hearer of the sen­tence Leslie is not a mother presuppose or believe that Leslie is a woman.

The point to be made is that only some information in a

INFORMATION IN REASONING 291

sentence constitutes the intended messa~e, whereas other information is tacitly assumed to be true. The sentences X is not a ~ainter and X is a painter explicitly communi­cate somethlng about the profession of X. That is the foreground information. Not explicitly communicated is e.~. that X is living, human. That is background infor­mation which is assumed to be true in both sentences. That background information is not easily available for a negation: X is not a ?ainter but a stone sounds at least strange. Similarly, If the analysis of Miller is correct, the sentence Leslie is not a mother when used in a context that necessitates to interpret Leslie as a man, will cause the hearer some difficulty.

The topic of the present paper is new and old information, explicitly communicated and presupposed information or foreground and background information. More specifically the present study will demonstrate the role of foreground and background information in simple reasoning tasks. Not all information is equally likely to be background information. Some factors will be discussed that deter­mine what information is likely to be foreground infor­mation and what information is likely to be background information.

Presupposed or Background Information

In the first experiments to be reported, very simple problem solving tasks have been used, each of them involving a negative sentence. The task is such that in order to arrive at the conclusion, a certain proposition has to be negated. It is assumed that the solution of these tasks is straightforward if a subject can negate that proposition. If many subjects are not able to solve the task, this will show that that proposition is wrongly presupposed to be true. This existence of presuppositions is inferred from the difficulty of the task. A task is considered to be difficult when it can hardly be solved or when it takes a relatively long time to solve it.

Experiment I

The first experiment has been done in collaboration with Levelt. The starting point of this experiment was the following well known problem: "Two Indians, a tall one and a small one were sitting at a fence; the smaller one was the son o~ the taller one; the taller one was not the father of the smaller one. How is this possible?" Most people have great difficulty in solving this prohlp.m. They don't manage to deny the masculinity of the tall

292 L.G.M. NOORDMAN

Indian. The ne~ation in the tall one is not the father of the small one did not affect the feature male. This indicates that male is a presupposition of father which agrees with Miller's analysis.

It could be argued however, that the difficulty of the problem resides not only in the presuppositional struc­ture of the kinship terms but also in some other factors. Indians are normally assumed to be male Indians. This factor can be eliminated by constructing the problem in the form: A is the son of B, B is not the father of A. Another factor attributing to the difficulty of the nrob­lem might be the presence of kinship terms of the same sex in both sentences. \-lhen kinship terms pontrasting on the gender component are used in the sentences, it is less likely that the gender is background information and consequently more likely that the gender will be affected by the negation. If this is correct, the fol­lowin~ problem should be much easier: A is the daughter of B. B is not the father of A. It is assumed that the context determines what information is background and what foreground information. Similar remarks can be made with respect to the problems A is the daughter of ~, B is not the mother of A and A is the son of B, B is not the mother of A.

These four problems constituted the items of the first experiment. Because of the riddle character of the items, each subject was given only one item. Each item was presented to seventeen SUbjects. An item followed by the question how is this nossible was presented acoustically. The time was measured from the end of the presentation of the question until the subject gave the answer. If the subject did not give the answer within 120 seconds he was considered unable to solve the problem and the experimenter stopped the session.

The experimental data are the latencies and the number of errors. The latencies have been analysed with the Mann-~.,rhi tney-U test. To subj ects who gave an incorrect answer or no answer at all, the highest possible ran~ was attributed in these tests. The median latency and the number of errors for each item are represented in Table 1. The median latency for item 1 is not reported. Because that item has not been solved by more than one half of the subjects, the median cannot be computed in a non-arbitrary way.

INFORMATION IN REASONING 293

Table 1. Items, median latencies (sec) and number of subjects*who gave the correct answer (Expt. 1) .

Item Median Number Latency Correct

1. A is the son of B + 2 B is not the father of A

2. A is the daughter of B 68 9 B is not the father of A

3. A is the daughter of B 26 I? B is not the mother of A

4. A is the son of B 11 17 B is not the mother of A

* n = 17 per item

+ for absence of median, see text.

The results confirm the predictions with respect to the hardness of the problems. Many subjects could not solve the problem they were f,iven, and if they could solve the problem, it took a relatively lonf, time. It can be concluded that the subjects have difficulty in negating the sex component. The gender is a presupposition or background information. The analysis of the errors con­firms this conclusion: stepfather and stepmother are frequent reactions. ----

Items with kinship terms of different sex are overall easier than items with kinship terms of the same sex (z = 2.77, £ <.01). So in the former items where the kinship terms contrast on the gender component, the gender is less likely to be background information and more available ~or negation than in the same-sex items.

There is an additional significant result. The items with B is not the father of A are more difficult than the items with B is not the mother of A (z = 6.2?, £<.001) Apparently, it is easier to conclude from B is not the mother that B is the father than from B is not the father that B is the mother. One could say that the masculinity of father is more strongly presupposed or background information than the femininity of mother. This asymmetry will be discussed later on.

The gender of the subjects did not affect the latencies; male and female subjects reacted in the same way.

294 L.G.M. NOORDMAN

The conclusion so far is that the ~ender is the back­~round information of the kinship terms father and mother in these problems. It is plausibIe then that the foreground information is parenthood. A negation affects the foreground information. So it is expected that the meaning component parenthood is most likely to be affec­ted by a negation. This prediction has been tested in two problems, where both the gender component and the parenthood component can be negated.

Experiment II

The first problem is: A is the father of B. A is the grandfather of C. B is not the father of C. what could B be of C? There are three possible answers: mother, uncle and aunt. Mother differs from father with resnect to the gender; uncle differs from father with respect to parenthood; aunt differs from father with respect to both meaning-components. If parenthood is the fore~round in~ormation and the sex the background information, the most frequent answer will be uncle. Similar predictions can be made with respect to the problem: A is the mothen of B. A is the ~randmother of C. B is not the mother of C. what could B be of C?

The experiment has been run by students of Leve1t. Each problem has been presented to 40 subjects. The experi­ment was balanced with respect to the ~ender of the experimenter and of the sUbjects. These variables, however, had no effect.

The results of the father-~randfather problem confirm the predictions. Twenty-e1~ht subjects ~ave a correct answer; the answer uncle was ~iven 20 and mother 8 times. Moreover, 11 out of the 12 erroneous answers were male terms. The conclusion is that the sex component is the back~round information and parenthood foreground infor­mation. An additional result is that no subject ~ave the answer~. Apparently, the negation affects only one meanin~ component.

The results of the mother-~randmother problem also con­firm the predictions. The answer aunt is ~iven by 1? subjects and father by 15 subjects:--But 12 out of the 13 erroneous answers were female terms. The results are less dramatic than those of the first problem. This is in agreement with the observed asymmetry between father and mother in the previous experiment.

Again no subject gave the answer uncle which differs on

INFORMATION IN REASONING 295

two meanin~ components from mother.

The fact that in producin~ the answer only one feature is changed, is in complete a~reement with the rule Of minimal contrast formulated hv Clark (lQ70) for word association data. That rule says: chan~e the si~n of only one feature, preferahly the last feature in the list. The most frequent association to man is '!lOTTlan where only the sex is changed, then boy ImDlyin~ a change in the feature adult, and then girl, implyin~ a chan~e in both features. This rule of mlnimal contrast has also been found by Levelt, Schroeder and Hoenkamp in the domain of motion verbs (in this volume).

Dif~erences in background information

The results so far demonstrate that the gender is hack­~round infor~ation of the kinship terms. A second result was that the masculinity of father is more background information than the femininity of mother. In other words father and mother are asymmetric with respect to back­ground information. An interesting question is whether there are kinship terms that are more symmetric than father and mother. According to Lyons (1968), that is the case for brother and sister: "The fact that there is no superordinate term'- for the two complementaries brother and sister, is prima facie evidence that the opposition between the two terms is semantically more important than what they have in common." Conseauently, the asymmetry found for father and mother should not be found for brother and sister. On the other hand, the results for items with ~ and daughter should exhibit the same asymmetry as those for father and mother.

Experiment III

The items are represented in Table? Condition I con­tains the not son and not dau~hter items, e.g. A is the father of B. B is not the son of A. Condition II con­tains the not brother and not sister items, e.~. A is the brother of B, B is not the brother of A. Eac~ob­lem in condition I has been given to ten subjects; each problem in condition II to twelve SUbjects. Each sub­ject was given one item. The design was balanced with respect to the gender of the SUbjects.

Assuming again that the gender is the background infor­mation of these kinship terms, it is predicted that sub­jects will need a relatively long time to solve these problems, if they can be solved at all. The other

296 L.G.M. NOORDMAN

prediction is that the B is not the son items are more difficult than the B is not the dauBhter items and that there is no difference between B is not the brother items and B is not the sister items.

Table 2. Items, median latencies (sec) and number of correct answers (Expt. III).

Item

Condition I (n=lO per item)

1. A is the father of B B is not the son of A

2. A is the mother of B B is not the son of A

3. A is the mother of B B is not the dau~hter of A

4. A is the father of B B is not the daughter of A

Condition II (n=l? per item)

1. A is the brother of B B is not the brother of A

2. A is the sister of B B is not the brother of A

3. A is the sister of B B is not the sister of A

4. A is the brother of B B is not the sister of A

Median Latency

+

13

9

10

+

+

34

+

+ for absence of median, see text.

Number Correct

3

7

7

9

6

6

8

4

The results are presented in Table 2. A~ain no medians have been reported for items that have not been solved by at least one half of the subjects. The latencies have been analysed with the Mann-Whitney U test. The sex or the subjects did not have a differential effect on the latencies.

The results are in a~reement with those of Exneriment I: subjects have difficulty in denying the gender. Many

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subjects could not solve the problem they were ~iven. The ~ender is the background information in these prob­le'TIs •

The latencies for the items B is not the son are lon~er than for the items B is not the daughter (z = 1.71, E <.05 one tail). The masculinity of son is more back­ground information than the femininity of daughter. On the other hand, the items B is not the sister were as difficult as the items B is not the brother as was expec­ted (z = 0.46, ~ = .65). The gender is equally back­ground informat10n in brother and sister.

The asymmetry between father and mother and between son and daughter has been interpreted in the sense that the masculinity of these male terms is more background infor­mation than the femininity of these female terms. Male is background information just as the features e.g. human, livin~, concrete. These features are sometimes called higher order presuppositions; they are presuppo­sitions of presuppositions: man presupposes human, human presupposes living, livin~ presupposes concrete. According to linguists, higher order presunpositions are less likely to be affected by a negation than first order nresunnositions. The sentence this child is not married is less strange than the sentence this stone is not married. By attributing not married to stone not only the presupposed information of the feature adult, but also of the featur$ living and human are denied. Another example comes from Lakoff (1972):

1. few men have stopped beating their wives. 2. some men have stopped beating their wives. 3. some men have beaten their wives.

Sentence 1 presupposes sentence 2; ? is the first order presupposition of 1. Sentence 2 presupposes sentence 3; 3 is the second order presupposition of 1. A first order presunposition can be suspended, as is demonstrated in 4:

4. ~ew men have stopped beating their wives, if any at all have.

A higher order presupposition cannot be suspended: sen­tence 5 is not acceptable:

5. few men have stopped beatin~ their wives, if any have ever beaten them at all.

In line with this analysis one could say that in these

298 L.G.M. NOORDMAN

problems the masculinity of father behaves like a pre­supposition of a higher order than the femininity of mother. The negation is less likely to affect the fea­ture male of father than the feature female of mother. The same remark can be made with respect to the asYm_ metry between ~ and dau~hter.

Many word pairs in natural langua~e have such an asymme­try. Examples are marked-unmarked word pairs like good and bad, lOig and short, and positive and negative pre­positions 1 ke above and below. Similar psycholo~ical phenomena have been found for these categories of con­cepts as for the kinship terms father and mother. In a recall task (Clark & Card, 1969) bad is recalled as good more frequently than that goo~ is recalled as bad. The transformation of isn't above 1nto below took more time than the transformation isn't below to above (Voun~ & Chase, 1971). With respect to marked and unmarked words e.g. g?Od and bad. Clark (1975) distinguishes bet­ween the nom1nal sense of good as 1n how good was the film and the cont~astive sense of good as in the film was-good. A marked word has only the contrastive sense. These senses are represented by Clark in the followin~ feature notation: goo~ in the nominal sense has the -components ~+ evaluat1ve (polar»; in the contrastive sense it has the components (+ evaluative (+polar», bad has the components (+ evaluative (- polar». The asymmetry consists in the fact that the nominal sense which exists for only the unmarked concept, is simpler because it is not specified for polarity. For the posi­tive and negative prepositions Clark proposes the fol­lowing feature notation: above is coded as (+ vertical (+ polar»; below as (+ vertical (- polar». The asymmetry is now explained by postulating that the coding + is more easily obtained than the coding -. This explanation is also offered as an alternative explanation of the asymmetry between marked and unmarked words.

An intriguing question is where this asymmetry comes from. Why is masculinity more background information than femininity in the previous experiments; why can only good be used in a nominal sense and not bad. There are certainly biological, educational and cultural fac­tors involved. Clark (1973a) has discussed spatial words in this respect. This problem however, will not be discussed at present. The question to be studied now is how the asymmetry has to be described. Is it due to the lexical coding of the concepts themselves or is

INFORMATION IN REASONING 299

it due to the use of the concepts. In other words, can the asymmetry sufficiently be described in terms of dif­ferential lexical codin~ of the concepts or does the asymmetry depend on factors such as foreground and back­ground. The problem to be studied at present is whether the asymmetry between male and female kinship terms can be influenced by manipulating the foreground and back­~round information.

Variability o~ Fore~round and Background Information

In terms of background and foreground information, the asymmetry consists in the fact that a particular ~eaning component e.g. the gender, is more back~round informa­tion in one word than in another word. In that case, the asymmetry should disappear if that component is stressed as the fo~us of the communication. In terms of lexical codin~ however, the asymmetry consists in the ~act that the positive value of the meaning component can more easily be represented than the negative value. This asymmetry will not disappear if that meaning com­ponent is stressed.

In the following experiments the subject is given some information about a person X. He then has to make a decision with respect to X. In one case the criterion on which he has to decide is the generation; in the other case it is the gender.

Experiment IV

In this experiment, the task is such that the attention of the subject is directed to the generation. The problems were of the following form: A is the father of Br can B be the son of A. Items have been constructed wlth father, mother, ~ and daughter. The nature of the task stresses in fact the generation component as the criterion on which the subject has to make his decision. The answer is yes if and only if the kinship term in the second sentence is of another generation than the kinship term in the first sentence. It is clear that the gender component is quite irrelevant for the decision: if A is the father of B, B can be the son, but also the daughter of A. According to the foreground­background theory, it is easier to decide that B is male than that B is female. The reason is that the mas­cUlinity in father and son is more background information than the femininity in mother and daughter. Subjects will be more inclined to assume that B is male than that

300 L.G.M. NOORDMAN

B is female. The theory of lexical codin~ predicts the same results. In this case, the reason is that the positive value on the gender feature as such can more easily be represented than the negative value.

The items were presented visually. The sentences were presented the one after the other. The latency was measured from the onset of the presentation of the second sentence until the subject pressed a button. The experi­ment was balanced with respect to the number of items requiring the answer yes and no, with respect to the gender of the subjects, and with respect to the location of the yes and no button. There were 24 subjects, each of them being given all the problems.

Table 3. Items and mean latencies (msec.) (Expt. IV).

Mean Item Latenc~

1 A is the father of B· , B is the son of A 1634 2 A is the father of B· , B is the daulShter of A 1811

3 A is the mother of B-, B is the son of A 1641 4 A is the mother of B· , B is the daup;hter of A 1773

5 A is the son of B· , B is the father of A 1311 6 A is the son of B· , B is the mother of A 1819

7 A is the daughter of B· , B is the father of A 1465 8 A is the dau~hter of B· , B is the mother of A 1557

The results, shown in Table 3, confirm the predictions. The latency for the items with a male term in the second sentence was smaller than the latency for the items with a female term in the second sentence (z = 3.46, n< .001; Wilcoxon matched-pairs signed-ranks.) -

Experiment V

In this exneriment the attention of ths subjects was directed to the sex of the kinship terms. The problems were Of the following form: A is the father of B. is A male? Items have been constructed with the terms father, mother, son and daughter for the first sentence and with the-cQncepts male and female for the second sentence. According to the theOry of lexical coding, the latency for the male items should be shorter than for the female

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items for the same reason as in the previous experiment. Accordin~ to the theory of foreground-background infor­mation, the latencies should not differ, because the gen­der is in both cases equally in the foreground. The exp­erimental procedure was the same as in the previous exp­eriment. The number of subjects was twelve.

'T'able ~ . Items and mean latencies (msec.) (Expt. V) •

Item Mean Latenc~

l. A is the father of B, A is male 1135

2. A is the mother of B, A is female 1253

3. A is the son of B, A is male 1238

4. A is the daughter of B, A is female 1173

The results shown in Table 4 support the fore~round­background theory. There is no difference in the laten­cies between the items with A is male and A is female (z = 0.21; ~ = .83; Wilcoxon matched pairs signed-ranks).

Several other experiments with marked and unmarked word pairs lead to the same conclusion (Noordman, 1976). If a subject knows that he has to answer the question, e.g. which one is the highest or which one is the lowest and if the required information is not stored in a way congruent with one of these questions, there is no dif­ference in RT between the marked and the unmarked question.

The conclusion is that the asymmetry between male and female kinship terms as well as between marked and unmar­ked adjectives depends on the background-foreground dis­tinction, the asymmetry can best be described in terms of background and foreground information.

Conclusion

The results of the present experiments lead to the conclusion that the meaning components of th~ kinship terms differ with respect to foreground and background information. Foreground information is explicitlY com­municated information; background information is not the proper content of the message; it is assumed to be true. In general the generation is the foreground information of the problems being studied and gender is the back­ground information. For whatever reason however, the

302 l.G.M. NOORDMAN

masculinity of many male kinship terms is more back­ground information than the femininity of the corres­ponding female terms. When processing a negation, one searches the meaning component the negation refers to, starting with the information that is most in the foreground. This explains first the difficulty of the items in the negation experiments and second the asym­metry between the tasks with male and female kinship terms. That masculinity is more background information and more likely presupposed than femininity accounts also for the results of the latter experiments where a decision had to be made with respect to the ~ender or the generation. Explaining the asymmetry between male and female kinship terms as well as between unmarked and marked adjectives in terms of back~round and foreground information has the advantage that one can easily account for the effects of contextual factors, lin~uis­tic or psychological, on reasoning tasks with these terms.

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