Threats to Internal Validity

Threats to Internal Validity

(Shadish, Cook, & Campbell, 2002)

1. Ambiguous temporal precedence. Based on the design, unable to determine with certainty which variable occurred first or which variable caused the other. Thus, unable to conclude with certainty cause-effect relationship. Correlation of two variables does not prove causation.

2. Selection. The procedures for selecting participants (e.g., self-selection or researcher sampling and assignment procedures) result in systematic differences across conditions (e.g., experimental-control). Thus, unable to conclude with certainty that the “intervention” caused the effect; could be due to way in which participants are selected.

3. History. Other events occur during the course of treatment that can interfere with treatment effects and could account for outcomes. Thus, unable to conclude with certainty that the “intervention” caused the effect; could be due to some other event to which the participants were exposed.

4. Maturation. Natural changes that participants experience (e.g., grow older, get tired) during the course of the intervention could account for the outcomes. Thus, unable to conclude with certainty that the “intervention” caused the effect; could be due to the natural change/maturation of the participants.

5. Regression artifacts. Participants who are at extreme ends of the measure (score higher or lower than average) are likely to “regress” toward the mean (scores get lower or higher, respectively) on other measures or retest on same measure. Thus, regression can be confused with treatment effect.

6. Attrition (mortality). Refers to dropout or failure to complete the treatment/study activities. If differential dropout across groups (e.g., experimental-control) occurs, could confound the results. Thus, effects may be due to dropout rather than treatment.

7. Testing. Experience with test/measure influences scores on retest. For example, familiarity with testing procedures, practice effects, or reactivity can influence subsequent performance on the same test.

8. Instrumentation. The measure changes over time (e.g., from pretest to posttest), thus making it difficult to determine if effects or outcomes are due to instrument vs. treatment. For example, observers change definitions of behaviors they are tracking, or the researcher alters administration of test items from pretest to posttest.

9. Additive and interactive effects of threats to validity. Single threats interact, such that the occurrence of multiple threats has an additive effect. For example, selection can interact with history, maturation, or instrumentation.

 

 

 

Research Theory, Design, and Methods Walden University

© 2016 Laureate Education, Inc. Page 2 of 2

Reference Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and quasi-

experimental designs for generalized causal inference. Boston, MA:

Houghton-Mifflin.

 

 

  • Threats to Internal Validity
    • Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and quasi-experimental designs for generalized causal inference. Boston, MA: Houghton-Mifflin.
StudyAcer
Calculate your paper price
Pages (550 words)
Approximate price: -
StudyAcer

Quality Researched Papers

We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.

StudyAcer

Qualified Writers

We have hired a team of professional writers experienced in academic and business writing. Most of them are native speakers and PhD holders able to take care of any assignment you need help with.

StudyAcer

Unlimited Revisions

If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account.

StudyAcer

Prompt Delivery

All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. We will always strive to deliver on time.

StudyAcer

Original & Confidential

We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text.

StudyAcer

24/7 Customer Support

Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.

Try it now!

Calculate the price of your order

Total price:
$0.00

How it works?

Follow these simple steps to get your paper done

StudyAcer

Place your order

Fill in the order form and provide all details of your assignment.

StudyAcer

Proceed with the payment

Choose the payment system that suits you most.

StudyAcer

Receive the final file

Once your paper is ready, we will email it to you.

Academic Writing Services

If you are looking for exceptional academic writing services, then you are in the right place. Studyacer offers customised academic assignments and academic papers for students at all levels.

StudyAcer StudyAcer

Essays

Essay Writing Help

Writing an essay can be a challenge. However, we know what every student needs. And we purpose to deliver. Here at StudyAcer, we do all we can to help with academic essays and assignments. We have a dedicated team of professional essay writers.

StudyAcer StudyAcer

Assignment

Assignment Help

We understand students need satisfactory results. Our cheap assignment writing service helps and never leaves any doubt. We always strive to ensure the ultimate and best results. It is our joy to offer a cheap reliable essay writing service.

StudyAcer StudyAcer

Term paper

Term Paper Help

Have you been asking yourself, where can get a pre written research papers for sale? Worry no more, the fact that you have a term paper that is due tonight and you haven’t touched it. At Study Acer it is our responsibility to get your paper on time.

StudyAcer StudyAcer

Dissertation

Dissertation Writing Service

Several master’s students seek professional help with their thesis.Students from different parts of the world experience different challenges. Dissertations have different stages and the challenges are different too. Do not struggle in silence, order now .