The concept of validity

It refers to quality which could be applied to any aspect pertaining to research process. In regard to procedures of measurement it implies to whether research instrument measures what it is suppose to measure. Basically there are two approaches through which validity of an instrument could be checked: a logical link established between the objectives of the study undertaken and the instrument answering established set of questions, using therefore statistical analysis for the purpose of demonstrating the link.

 Validity could be of three types:

  • Face and content
  • Concurrent and predictive
  • Constructive validity

The ability of producing consistent measurements every time refers to the reliability of an instrument. When an instrument is administered under  similar conditions obtaining same results, it is regarded as the ‘reliable’ instrument- the reliability increases with increase in the similarity of results. Reliability can be looked from two sides:

  • Reliability or the extent of accuracy
  • Unreliability or the extent of inaccuracy

If the wording of questions is ambiguous, there is a change in the physical setting for the purpose of data collection, mood of respondent’s while providing information, interviewer and interviewee’s interaction, and the instrument’s regressive effect are few factors that affect the research instrument’s reliability.

Procedures for determining reliability are external and internal consistency. Parallel forms and test/re-test of the same test form the two procedures which would determine the research instrument’s external reliability. The internal consistency involves the split-half technique.

Tips to the researcher

It is significant to have a mutual understanding between the guide and the researcher and therefore one should consider the following points:

1. The guide should show equal interest in the problem as the researcher does. There are times that the project can take more time which does not imply any mistake on part of the guide, so both the guide and the researcher should understand that the outcome of the investigation may not be of standard quality.

2. The researcher should not completely depend upon the guide to develop the problem, rather he should do on his own and then exchange notes with the guide.

3. The guide should not be hammered too frequently. The guide himself does not know the complete answer to the research problem, if he knew it would not form a research problem.

4. Usually the guide acts as the chairman for the oral examination committee.

Use of the library:

  • The information regarding all papers published and the titles, author and short description of the contents of the paper are all contained in ‘Science Abstracts’. The references of the journals in which the detailed articles appeared are also included in it.
  • Instead of making notes it is better to have Xerox copies of the paper of interest, which is a time consuming work with no credits.
  • The researcher should hold one’s personal reference card for brief details to be noted thus providing quick and handy reference.
  • The researcher will have to glance through all the periodicals and the journals as there is no short cut to search material.
  • Translations are mostly available for almost all journals so the material searched should be on international basis.
  • It becomes important to have library knowledge of at least one foreign language.
  • Any difficulties found in tracing the material should be directly referred to the librarian.