Cecilia Gerald
ED 7202
Assignment 1
Threats to Internal and External Validity
My action research project will be implemented in order to determine the effects of a selfmonitoring strategy (treatment) on the disruptive behaviors of a small group of five students. A
single-subject research design, ABA, will be used. The researcher will collect baseline data to
gauge students’ engagement in disruptive behaviors (A), followed by the introduction of
treatment (B), and lastly the use of the treatment will be faded (A) to evaluate the results.
Threats to Internal Validity
History: This is a valid threat to the study because other events, such as a particular time of the
day or altercations with other students, may occur.
Maturation: This is not a valid threat because the treatment will be given for a period of only 4
weeks, during which no significant levels of maturation are anticipated.
Testing/Pre-Test Sensitization: This is not a valid threat because there will be no pre-test given to
the students. The collection of baseline data (observation of frequency of disruptive behaviors)
will occur before treatment.
Instrumentation: This is not a valid threat because the instruments used in the study (selfmonitoring charts) are identical and will not be changed throughout the treatment period.
Mortality: This is a valid threat. If students do not participate during the entire treatment period,
due to suspension, withdrawal from treatment or absence from school, the results will be
inflated.
Statistical Regression: This is a valid threat because there are only 5 students participating in the
experiment, which could produce statistically significant results that are extreme.
Differential Selection of Subjects: This is a valid threat since students will not be randomly
assigned, and they may have different developmental and cognitive levels at the onset of
treatment.
Selection-Maturation Interaction: This is a valid threat because students have different
maturation levels, which may affect their response to treatment.
Threats to External Validity
Ecological Validity: This is a valid threat because this treatment may have different results on
students in different environments due to variables, such as population type (special education
vs. general education population), class size, etc.
Generalizable Conditions: This is a valid threat because this treatment can be replicated but may
have different effects due to variables such as maturation, history, etc.
Pre-Test Treatment: This is not a valid threat since students will not be pre-tested for this study.
Selection-Treatment Interaction: This is a potential threat because students will not be chosen
randomly. They will be identified by their teacher as having disruptive behaviors and this will be
the selection process for participation in the study.
Specificity of Variables: This may be a valid threat because if the target behaviors are not
operationally defined, they may not be observed and measured appropriately.
Multiple Treatment: This is not a valid threat since there will only be one type of treatment given
during this study.
Treatment Diffusion: This is not a valid threat because there is only one experimental group in
this study that will be receiving treatment.
Experimenter Effects: This is a valid threat because the researcher is familiar with the students
through a recent student teaching experience, which may have an effect on the treatment results.
Reactive Arrangements/Participants Effects:
Hawthorne Effect: This is a valid threat because the students will be made aware of the
treatment being given for disruptive behavior in order to create student buy-in. This may
affect the frequency in which they engage in disruptive behaviors.
Compensatory Rivalry Effect: This is not a valid threat because the treatment group is not
being compared against any other group for this study.
Placebo Effect: This is not a valid threat because the students will only be given
treatments that are intended to have an effect.
Novelty Effect: This is a valid threat because this treatment has not been used with these
students before, and their potentially heightened interest in it may have an effect during
the onset of treatment.
References:
O’Connor-Petruso, S. (2010). Descriptive Statistics Threats to Validity [PowerPoint slides].
Retrieved from http://bbhosted.cuny.edu/webapps/portal
Siegle, D. Principles and Methods in Educational Research. Retrieved from
http://www.gifted.uconn.edu/siegle/research/Experimental/experimentInstructorNotes.ht
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