1. RELIABILITY OF QUANTITATIVE & QUALITATIVE RESEARCH TOOLS

2. DEFINITIONS OF RELIABILITY
Throndike : Reliability is the consistency of a test with which it measures whatever is supposed to be measured. Test reliability is usually thought as the degree to which the test is free from compensating error.
Gronlund and Linn : Reliability refers to consistency of measurement, that is how consistent test scores or other evaluation results are from one measurement to other.

3. CHARACTERSITICS OF RELIABILITY
Consistency
Accuracy
Does not ensure validity

4. MEASUREMENT OF RELIABILITY
Test-Retest method
Split half method
Parallel form method
Rational equivalence

5. TEST-RETEST METHOD
Same test administered twice to the same group of pupils with a given time interval between 2 tests
The test scores are correlated
Product moment method of correlation
High correlation between 2 set of scores indicate test is reliable

6. LIMITATIONS
Short time interval b/w two administrations – memory and practice effects (overestimate reliability)
Long time interval b/w two administrations – change in behavior due to growth and maturation (underestimate reliability)
To avoid this-
Time interval b/w two tests should neither be very long nor be very short.

7. PARALLEL FORM METHOD Two alternate forms of test are used
Two forms must be homogenous in all respects
One form of test administered on students and on finishing immediately another form of test is supplied to same group
Scores obtained are correlated which gives estimate of reliability

8. PRECAUTIONS
Not to have items b/w two tests very similar in two tests (to avoid very high reliability)
Not to have items b/w two tests very much different in two tests (to avoid very low reliability)

9. SPLIT HALF METHOD Test is administered once on a sample
All items are arranged in increasing order of difficulty
After administering test is divided into equal parts
Scores are made in two sets obtained from odd numbers of items and even number of items separately
Co-efficient of correlation calculated
Spearman Brown formula

10. RATIONAL EQUIVALENCE METHOD
Kuder-Richardson reliability
Method based on single administration
Test is homogenous in nature
Correlation between items are equal
All items measure same ability

11. FACTORS AFFECTING RELIABILITY
EXTRINSIC FACTORS
INTRINSIC FACTORS

12. INTRINSIC FACTORS
Length of the test
Homogeneity of items
Difficulty value of items
Discriminative value
Test instructions

13. Extrinsic factors Group variability Guessing and chance errors
Environmental conditions
Momentary fluctuations

14. QUANTITATIVE & QUALITATIVE RESEARCH
Quantitative research utilizes quantitative data (closed ended) and data is collected through questionnaire, tests, attitude scales, rating scales.
Qualitative research utilizes qualitative data (open ended) and data is collected through questionnaire, observation, interview, schedule

15. QUANTITATIVE TOOLS & THEIR RELIABILITY
ACHIEVEMENT TESTS
Used to measure what individual has learned- present level of performance. Achievement test scores are used frequently in evaluating influences of courses of study and teacher methods.
TEST-RETEST & SPLIT HALF METHOD is used to find reliability

16. APTITUDE TESTS
Aptitude tests are used to measure person’s potential ability in an activity of specialized kind. It predicts success in some occupation, academic or training courses.
Some aptitude tests are clerical aptitude test battery, a battery of mechanical aptitude test.
TEST-RETEST & SPLIT HALF METHOD is used to measure reliability
PARALLEL FORM METHOD is used if multiple forms of test are present

17. RATING &ATTITUDE SCALE
Rating scale refers to a scale with a set of points which describe varying degree of dimension of an attribute being observed. Observer may be asked to judge the behavior he observes and classify it into categories.
Attitude scale asses attitude and belief of an individual. Positive and negative effect associated with some object (institution,slogan,symbol,job)
SPLIT HALF METHOD, PARALLEL FORM METHOD are used to find reliability

18. QUESTIONNAIRE
Systematic compilation of questions that are administered to a sample of population from which information is desired.
Both quantitative and qualitative measuring tool
TEST-RETEST & PARALLEL FORM METHOD is used to measure reliability.
Comparison of responses of an alternate form with original forms of questionnaire

19. FACTORS AFFECTING RELIABILITY OF QUESTIONNAIRE
Confusing or Ambiguous Questions
Prejudice regarding sample

20. QUALITATIVE RESEARCH TOOLS & THEIR RELIABILITY
OBSERVATION
Process in which one observes what is occuring in real life situation and classify, record, interpret the happenings. It is one of the oldest technique of data collection.
RELIABILITY:
Inter observer aggrement
Single observer
Reliability among different observers should be 90% or higher.

21. PROBLEM IN OBSERVATION
When researcher is sole observer-
he or she could be biased
SOLUTION
Engage other trained observers
Other observers should be kept unaware about the purposes and hypothesis of study – BLIND
Persons under observation are unaware that they are being observed – DOUBLE BLIND

22. INTERVIEW
Process of communication and interaction in which interviewee gives needed information verbally in face to face situation.
RELIABILITY:
Restating questions in slightly different form
Repeating the interview
Different interviewers employed

23. Reliability of interview is affected by-
Desire of interviewee to answer according to social acceptance
Content and forms of question.
Physical setting or other distractions
Confidence of interviewee in interviewer

24. SECONDARY DATA
Account of events provided by a person who did not directly observe the events or objects
Reliability- by ensuring that:
Who collected the data
What were the sources of data
Was the data collected by using proper methods

25. CONCLUSION
Reliability is very important aspect of research. Without reliability one cannot think of quality research. As we have seen that if we do not apply the methods of finding out the reliability properly we will not get the data on which we can rely upon. Along with this researcher should also work to minimize the factors which affect reliability.

26. THANKS