Tribhuvan University, Nepal Masters in Arts Population Studies Research method in Population analysis Validity and Threats to validity If any mistakes, feel free to suggest me for the improvement. Hope its useful for reference thank You :)

1. Validity and Threats to
Validity
Presented By: Roji maharjan
Masters of Arts (T.U.)
Population Studies
Padma Kanya Multiple Campus

2. Objectives:
• To define validity
• To explain Methods of validity test along with its threats

3. Validity
• Validity is the extent to which a concept, conclusion or measurement is
well-founded, accurately measuring what it’s supposed to and
corresponds to real world.
• The term Validity means truth.
• Validity refers to the degree to which a test measure what is
claims to measure.
• Validity means to measure with reasonable degree of Accuracy.

4. Methods of validity
1. External Validity:
-External validity is related to generalizing.
-It is the degree to which the conclusions in study would hold for
other persons in other places and at other times.
-The variables used in the study are similar to those aspects as they
exist in the larger population.
-It occurs when the causal relationship discovered can be
generalized to other people, time and contexts.

5. Threats to External validity:
• Selection Bias: The sample is not representative of the population.
• History: An unrelated event influences the outcomes.
• Experimenter effect: The characteristics or behaviors of the
experimenter unintentionally influence the outcomes.
• Hawthorne effect: The tendency for participants to change their
behaviors simply because they know they are being studied.
• Testing effect: The administration of a pre-test or post-test affects
the outcomes.
• Aptitude-treatment: Interactions between characteristics of the
group and individual variables together influence the dependent
variable.
• Situation effect: Factors like the setting, time of day, location,
researchers’ characteristics, etc. limit generalizability of the
findings.

6. 2.Internal Validity
• It refers to the extent to which the results obtained in a research
study are a function of the variables that systematically
manipulated, measured, and observed in the study.
• It is the extent to which shows a cause-and-effect relationship
established in a study cannot be explained by other factors.
• It is the approximate truth about inferences regarding cause-effect
or causal relationships.

7. Threats To internal validity:
• History: the occurrence of events that could alter the outcome or the results.
• Maturation: any changes that occur in the subjects during the course of the
study that are not part of the study and that might affect the results of the
study.
• Instrumentation: concerned with the effects on the outcome of a study of the
inconsistent use of a measurement instrument.
• Testing: the possible effects of a pre-test on the performance of participants
in a study on the post-test.
• Statistical Regression: the tendency of extreme scores to move (or regress)
toward the mean score on subsequent retesting.
• Mortality: the loss of subjects from a study due to their initial non-availability or
subsequent withdrawal from the study.
• Selection: possibility that groups in a study may possess different characteristics
and that those differences may affect the results.

8. Construct Validity
• It refers to the degree to which inferences can legitimately be made
from the operationalizations in study to the theoretical constructs on
which those operationalizations were based.
• The quality of choices about the particular forms of the independent
and dependent variables.

9. Threats To Construct Validity:
• Mono-Operation Bias: it pertains to the independent variable, cause,
program or treatment in study – it does not pertain to measures or
outcome.
• Mono-Method Bias: it refers to your measures or observations, not to
your programs or causes.
• Interaction of Different Treatments:
• Interaction of Testing and Treatment.
• Restricted Generalizability Across Constructs.
• Confounding Constructs and Levels of Constructs.
• The “Social” Threats
• Inadequate Preoperational Explication of Constructs.
• Hypothesis Guessing

10. 4.Conclusion Validity
• Conclusion validity is the degree to which conclusions we reach
about relationships in our data are reasonable.
• It is relevant whenever we are trying to decide if there is a
relationship in our observations.
• It is the degree to which the conclusion we reach is credible or
believable.

11. Threats to conclusion validity:
A threat to conclusion validity is a factor that can lead you to reach
an incorrect conclusion about a relationship in your observations.
• low reliability of measures
• poor reliability of treatment implementation
• random irrelevancies in the setting
• random heterogeneity of respondents.
• low statistical power
• fishing and the error rate problem
• violated assumptions of statistical tests

12. Thank You!!