Designs that allow testing of hypotheses
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Describe pre-experimental, experimental and
quasi-experimental research designs.
Explain the types of conclusions you can draw
from data obtained in at least three different
types of research designs described.
Read a research article and describe the
research design
Describe the research design for your
research project.
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Qualitative – construct meaning
Descriptive – quantitative descriptive stats
◦ identifying characteristics of an observed
phenomenon or exploring possible associations
among two or ore phenomena.
 Examines a situation as it is
 Correlations
 Surveys, questionnaires, structured interviews,
checklists
 NO causality
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Variables
◦ Independent
◦ Dependent
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Experimental Designs
◦ Experimental
◦ Quasi-experimental
◦ Post Facto Designs
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Does not show cause & effect
Independent “variable” does not vary
Experimental/control groups not equivalent
or randomly selected
Usefulness: Forming tentative hypotheses 
more controlled studies
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One-shot experimental case study
Group
Time 
Group 1
Treatment (Tx)
Observation (obs)
One Group Pre/Post test
Group
Time 
Group 1
Obs
Tx
Obs
Static Group Comparison
Group
Time  Group 1
Group 2
Time 
Tx
---
Obs
Obs
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Random assignment of subjects  causality
Pre/Post test Control Group
Group
Randomly
Assigned
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Time 
1
Obs
2
Obs
Tx
Obs
Obs
Solomon Four-Group Design ◦ Does the pre-test impact the post test?
Group
Randomly
Assigned
Time 
1
Obs
Tx
Obs
2
Obs
---
Obs
3
---
Tx
Obs
4
---
---
Obs
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Posttest Only Control Group
Group
Randomly
Assigned
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1
Tx
Obs
2
---
Obs
Within Subjects Design –
Group
Time 
1
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Time 
Tx1
Obs
Tx2
Obs
i.e. one exam (Obs),
◦ Tx1 – some content taught with case studies, some
content taught by pure lecture
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Randomized subjects impossible or not
practical
Don’t control for all confounding variables need to account for them in discussion
Nonrandomized Control Group Pre/post
Group
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Time 
1
Obs
Tx
Obs
2
Obs
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Obs
See others on table
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After the fact
Results do not allow causality conclusions
i.e. study of students who have failed a
Grouponce andTime
course
areretaking it.
Prior Event(s)
1
2
Exposure (Exp)
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Obs
Obs
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A researcher studies the effects of two different kinds of
note-taking training (one of which is placebo) on the
kinds of notes that college students take. Her sample
consists of students enrolled in two sections of an
undergraduate course in educational psychology; with
the flip of a coin, she randomly determines which section
will be the treatment group and which will be the control
group. She analyzes the content of students’ class notes
both before and after the training, making the prediction
that the two groups’ notes will be similar before the
training but qualitatively different after the training.
Quasi-experimental: Nonrandomized control group
pre/post test (Design 8)
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Hoskins, et. al. article
Darland and Carmichael article
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Even with control groups, not all research
designs allow you to draw conclusions about
causality.
Pick a research design that allows you to
make the types of conclusions about the data
that you are interested in making.