TITLE LAYOUT
Instrumentation
Fritzie V. dela Cruz, RN, MAN
Nursing Research Instructor
Instrumentation
Refers to data collection instruments.
Cronbachs’ Alpha (range 0-1)
 0.7- 1.00 –reliable and acceptable
Validity and reliability of instruments.
Instruments of the Study
 Standardized instrument
- Site the author and the instruments’ cronbachs’ alpha
 It should have range of possible scores and scoring procedures.
 It must be valid, reliable and specific.
 Pilot study results must be present for any revised instrument
or newly developed instrument.
A. Face validity
B. Content validity
C. Criterion validity
D. Construct validity
Forms of instrument validity:
A. Face validity
 It is a strong indicator that an instrument is measuring
what is supposed to be measured by the researcher.
 Relies on subject judgment which ensures cooperation
of participants.
Forms of instrument validity:
B. Content validity
 High content validity will be achieved if the questions
include parts of content domain with right proportions.
Methods:
1. Panel of experts will check the validity of the
instruments.
2. Develop a test blue print made from the objectives.
Forms of instrument validity:
C. Criterion validity
 The results of the assessment instrument correlate with
another and these are related measures. (criterion)
Example: An instrument designed to measure the nurses
effectiveness on her duties should correlate with
the number of the positive patient feedback
acquired in the course of her whole week duties.
Forms of instrument validity:
D. Construct validity
 Instrument that measures a characteristic that cannot be
observed directly but exist assumingly as seen on
patterns of human behavior.
 The most difficult to measure
A. Face validity
B. Content validity
C. Criterion validity
D. Construct validity
Reliability
 It is about consistency and stability.
r - value
Verbal description
0.00 – 0.29
Little or weak positive (negative) correlation
0.30 – 0.49
0.50 – 0.69
Low positive (negative) correlation
Moderate positive (negative) correlation
0.70 – 0.89
High positive (negative) correlation
0.90 – 1.00
Very High or strong positive (negative) correlation
Types of Reliability
1. Test – retest (stability) reliability
 Test given to the same samples on two different occasions.
2. Interrater (equivalence) reliability
 There must be 2 or more raters
 Comparisons of raters or observers’ rating using the same
instrument.
3. Intrarater reliability
 Same assessment is completed by the same rater on two or
more occasions.
Types of Reliability
4. Split-half reliability
 Most popular test of reliability
Procedures:
a. Pilot test your instrument in a subject group
b. Split the group into half to score separately
c. Correlate their scores.
5. Test Item Analysis
 Used when developing examinations or tests
 Do a (Kr) Test – Kuder and Richardsons test
Internal and External
Validity of Instruments
Internal Validity
 It refers to how accurate the results are and making sure that the
findings of the study are correct.
Six Threats to internal validity:
 Selection bias
 History
 Maturation
 Testing
 Instrumentation change
 Mortality
External Validity
 It refers to the accuracy of the study that can be applied to other
group or situation.
Threats to External Validity:
A. Hawthorne effect
 Participants cooperate because they are aware that they are being observed.
B. Experimenter effect
 The subjects’ behaviour were influenced by the researchers’ behavior.
C. Nocebo effect
 When the participant perceive side effects from ineffective treatment
Threats to External Validity
D. Placebo effect
 When participants believe that the treatment (ineffective treatment) can
alleviate symptoms by expecting that the treatment will work.
E. Rosenthal effect
 Respondents’ answer was influenced by the researchers’ behavior.
F. Reactive Effects of the pretest
 Sensitization of participants to the experimental treatment through
pretesting.
Developing a Research Instrument.
 A research instrument must have acceptable
reliability and validity to measure the variable of
interest.
 If the researcher will not be able to find a suitable
instrument, a new instrument or scale must be
created.
Guidelines in constructing a questionnaire:
1. Keep it as short as possible
 Ask yourself, “What is the purpose of the information that i am asking?”
2. Remember to make it simple and concrete for respondents
 The questionnaire must be an easy to read and respond questionnaire.
3. Give a specific instruction which is straightforward
 Give a direct instruction on how you expect the participant to respond.
4. Use understandable, clear and simple language
 Avoid words that the participants will not understand like the technically
made jargons.
5. Provide a rationale for items with unclear purpose
 Each question must have a clear purpose.
Guidelines in constructing a questionnaire:
6. Check for assumptions that are expressed in your questions
 Remove the unwarranted assumptions in your questions. Consider the example below,
7. Don’t give clues in the questions that will give signals about preferred responses
 Let the participant describe accordingly.
8. Think in advance how you will code the responses
 Think of recoding the responses of participants into a data that is numerical and can be
statistically analyzed.
Guidelines in constructing a questionnaire:
9. Consistency check
 You may ask the same questions two or more times by using different terms. Consider the
example below that shows items 3 and 15.
10. Check for the validity of your questionnaire by conducting one or more pilot tests
 Do some test runs of your newly developed questionnaires.
Guidelines in constructing a questionnaire:
11. Examine your almost-final product one more time and be sure that your
needs are addressed
 Check your questions item by item.
 Make sure that each question is relevant to address your research
problem.
12. Make a presentable and professional looking questionnaire
 Have a clear print of your final instrument.