Danko Šipka

Because the Slavic inflections modeling project (which will ultimately provide complete data) remains in its initial stage , of necessity, I will focus on presenting some of the basic ideas, a general overview and, to a smaller extent, concrete experimental data which will be greatly expanded upon in the future

In its broadest sense, a decision can be defined as any act of selection among several possible options. In recent decades there has been numerous works both describing and formalizing the entire decision making process. Such works have primarily been accomplished in psychology where conscious decision making is analyzed and game theory where research is based upon the interrelation and interaction of two or more players. Both fields use such criterion as utility, risk, cost-benefit ratio, etc. More about these approaches can be found in Morrow (1994), Keeney (1996), Kozielecki (1995), von Winterveldt and Edwards(1986).

In the use of language, some situations embody conscious decisions involving the person one is communicating with -- the other player as it were. A situation where one must consciously choose an honorific or gratuitous form of address is a typical example of a game theory type of decision making. However, in the most cases, such decisions are unconscious and fail to take into account the other player, or, to be more precise, the other player is ultimately irrelevant in such decision makiing.

In Slavic morphology,one normally and unconsciously chooses a form of address from an array of possible forms, doing so in such manner that the interlocutor does not influence the choice. Nevertheless, there are situations in foreign language teaching where this theory operates very differently; where the Slavic language student consciously chooses a form as the result of interactions with his or her tutor. Similarly, decisions made by computer programs about forms of inflected Slavic lexemes can also be the result of a conscious decision made by the software author or programmer.

The first goal of this project is to present some Slavic morphological rules as the result of sequential decisions involving risk. The idea is that such modeling can enhance all such situations where decisions about Slavic inflection forms must be made. This task is practical in nature and the ideas and resources used are well known: a. form data from traditional grammars, b hierarchies used in linguistics to classify data, c. decision flowcharts from psychology and computer science

The idea behind this aspect of the project is very simple – to describe the broadest possible range of Slavic morphological forms using a minimal means of description. Needles to say that being parsimonious is one of the crucial requirements of any scholarly research.

The second goal is to develop data by asking the following questions: a. What is the best way to model decision process? b. Do native speakers choose Slavic inflection forms as a result of sequential decisions?

As one can surmise, such a task is laborious because in order to answer these questions one requiresextensive experimental data.

In the next part of this paper I will outline the way in which Slavic morphology is described in the most commonly used grammars and then present solutions for the first goal of the project as well as experimental data related to its second goal.

Table 1 illustrates the terminal nodes of the decision making process. The task of modeling the process consists of determining both the decision criteria and in which order they are used to direct each adjective to its node. In other words, the decision making process can be viewed as a set of paths which the adjectives of certain languages must pass before arriving at their correct terminal nodes.

The mathematical formula required to determine the minimal number of features (B) in order to distinguish a number of elements (N) can be written as :

and this borders on information overload.

Let's take a Serbo-Croatian example to see how these criteria (non-terminal nodes) can be reduced. First, one has to separatethe criteria which can be inferred from available grammars. These are presented in the Table 2:

Table 2

The first transformation of the "centipede" is to merge the nodes which are used by the small number of adjective stems. Consequently, we can merge nodes 2 and 3 because the ending -ši is attached to only three stems and it can be appended to the suppletive stems category. The second transformation consists of establishing a hierarchy while, at the same time, setting defaults for each level of the hierarchy. One of the possible results of this process is presented in the Figure 1

As mentioned previously, this is only one way of ordering decisions. Its purpose is merely to illustrate the reasoning behind making formalizations. Theoretically, we could first ask if the stem ends in -ak,-ok,-ek, then, check to see if it is long or short, etc. However, even in a setting of reduced information, one can find at least two useful applications of this type of modeling – foreign language teaching and computational linguistics. In foreign language teaching, the decision making process is used with a"human interface" and exceptions should be included gradually. A reduced decision making tree for a Serbo-Croatian comparison paradigm (with its human interface) can have the following form:

1. Learn the list of supletive stems and, if adjective is one of these, use the supletive form.But if it is not:
2. check if the stem has one syllable and a long vowel, if so, palatalize the last consonant and add -i. If the stem does not belong to this category, use -iji

This simple decision making heuristic gives the right form of comparative in the vast majority of cases. This teaching process can include further nodes and thus reduce the margin of error. Exactly how this is accomlished is dependent on the concrete second language teaching approach (see the review of this in McLaughlin 1987).

Their basic corresponding comparative rule is:

Table 3

The adjectives this rule does not account for will simply have their comparative form written in the dictionary entry, as in: zao,zla,zlo,gori; tijesan,sna,sno,tješnji;

All this can be applied to both the Polish and Russian comparative paradigms and numerous other segments of morphology. However the material herein presented is sufficient to illustrate some key ideas.

The questions to be asked now is how to determine: a. what is the optimal content of the decision node? b. what is the optimal number of nodes? c. how should the decision nodes be ordered? There are two basic sources of data which can be used for these purposes. One is frequency count from the representative corpora for a given language. One might want to organize the decision making tree in such a manner so that the minimal number of nodes cover the most frequent cases. The second source data comes from the psycho-linguistic experiments in learning foreign language forms. Here, we can hopefully determine which specific node order makes it easier for a student to acquire a set of forms.

Turning to the second task of this project -- asking if native speakers of Slavic languages really generate morphological forms as part of sequential decisions -- we want demonstrate how this can investigated by using the example of the genitive endings of Polish nouns. Using the previously presented pattern and with certain degree of simplification, the Polish genitive ending decision making tree can be modeled as follows:

A simple psycho-linguistic experiment has been conducted in order to check if the decision-making tree previously exhibited has anything to do with the way people process this kind of information. The subjects were presented with nominative choices along with correct genitive forms of different Polish nouns and asked to verify if the forms were correct or not. The forms belonged to the lexemes split into four groups: non-masculine nouns: 1 feminine nouns ending in -a, 2 declinable neuter nouns; masculine nouns: 3 inanimate masculine nouns with consonant ending, 4 animate masculine nouns with consonant ending

Table 4

Fity normal adult Polish subjects were asked to confirm if the genitive form of the nouns from the Table 4 is correct or not. The reaction time of the decisions was recorded and the results presented in Table 5

Table 5: One-way ANOVA results

The results demonstrate that there is a statistically significant difference between the reaction time to differentiate between feminine/neuter nouns and masculine nouns. There can be various reasons for this including those mentioned earlier. However, further experimental work is needed to make any definitive claim.

Danko Šipka (d.sipka@tranexp.com)