Logiczne podstawy weryfikacji wewnętrznej badań kwestionariuszowych

Abstract

Two methods of analysis of research results obtained by means of questionnaires can be distinguished: external and internal ones. The purpose of the two methods is the evaluation of the quality of information recorded in completed questionnaires; but each one performs this task differently. The external method consists in having a recourse to information Obtained from the sources other than questionnaires themselves (such as, for example, official records, observation etc.). Instead, the internal analysis uses, for the purpose of evaluation, logical relationships which may occur between answers to questions in the questionnaire. On the basis of the definitions, of each of the known logical relationships it is possible to draw certain conclusions concerning the logical value of pairs of sentences in which the logical relationship occurs. So, for example, if two answers to a given question in a questionnaire are contradictory and have been found to be false, it is possible to ascertain, on such a basis, that the questionnaire is burdened with an error. The use of both methods simultaneously allows to draw additional conclusions that would not be obtainable with either method applied separately. For example, if we ascertained that a given answer A. implies logically another answer B, and, in addition, on the basis of information obtained from external sources, succeeded in finding out that the sentence B was false – we should be able to draw the conclusion that the sentence A was false, too. If the questionnaire is filled-out in a way contradictory with this conclusion, it must be burdened with an error. Using the concepts of logic and the logical theory of questions, the author discusses the application of the internal analysis method as well as simultaneous applications of the external and internal methods. Analysed are also logical and semantic inaccuracies of questions that may also be a source of errors in a questionnaire.