Vanessa DeVitoEducation 703.22
Spring 2008
Research Design Threats to Internal Validity Threats to External Validity Proposed Data Correlational Graphs References
Pre-Experimental Designs:
*Quasi-Experimental-Single Group
*One group-one designated treatment group (X¹) no control group (X²).
One-Shot Case Study:
*Single Group exposed to a treatment (X) and posttested (O).
*Symbolic Design:XO
History * Past literacy experiences and parental involvement.
Maturation*Repetition and “Spring Fever”.
Instrumentation *Self-created and therefore not pilot tested.
Mortality *Parental comfort level.
Generalizability*Impossible to get the same results elsewhere.
Ecological Validity*Conditioned responses based on surroundings.
Selection-Treatment Interaction*Not a random selection of students/parents.
Specificity of Variables*Variables should be consistent and measurable.
Experimenter Effects*Passive and Active Elements
Survey Questions/Student Attitudes:1. I like English Language Arts (ELA).2. My guardian(s) encourage me to read.3. I am confident in my reading and writing ability.4. I enjoy going to the library.5. English Language Arts (ELA) is easy for me.6. When I have free time I like to read.7. I like when my guardian(s) help me with my hw.8. I like when my guardian(s) help me study for a test.9. I like doing book reports.10.I like to talk to my guardian(s) about my
schoolwork.
Choice 1-Strongly DisagreeChoice 4-Strongly Agree
Posttest Results:Frequency of paired reading as compared to
Scholastic Reading Counts! scores.
*My child reads to me during the week.1.Never2.Once3. Twice4. 3x or more
0
20
40
60
80
100
120
0 1 2 3 4 5
LITE
RACY
ACH
IEVE
MEN
T SC
ORE
S
FREQUENCY OF PAIRED READING
Posttest Scores
The coefficient (.rxy) is 0.933. It is positive for line of best fit.
O’Connor-Petruso, S. (2008). Threats to Internal and External Validity PowerPoint.
Brooklyn College, Graduate Department of
Education.
http://www.physics.csbsju.edu/stats/QF_NROW_form.html