Quasi & Non-Experimental Designs
Sponsored Links
This presentation is the property of its rightful owner.
1 / 14

Quasi & Non-Experimental Designs PowerPoint PPT Presentation


  • 53 Views
  • Uploaded on
  • Presentation posted in: General

Quasi & Non-Experimental Designs. Quasi-Experimental designs: Not quite true experiments because the different groups/conditions are not created by __________________. Groups or conditions are defined by _____________ variable or a ______ variable.

Download Presentation

Quasi & Non-Experimental Designs

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Quasi & Non-Experimental Designs

Quasi-Experimental designs: Not quite true experiments because the different groups/conditions are not created by __________________. Groups or conditions are defined by _____________ variable or a ______ variable.

Non-Experimental designs – do not allow you to rule out many threats to _______________.


Quasi & Non-Experimental Designs

  • Those using ____ group, compare behavior across _____:

  • Time-series designs (quasi-experimental)

  • One group pretest-posttest (non-experimental)

  • Longitudinal design (non-experimental

  • Those using multiple, ____________ groups:

  • Pretest-posttest nonequivalent control group design (quasi-experimental)

  • Posttest-only control group design (Static-group design) (non-experimental)

  • Differential (Causal-comparative) design (non-experimental)

  • Cross-sectional design (non-experimental)


Summary of Quasi & Non-experimental designs


When would you use a quasi-experimental design?

  • When you want to investigate a relationship but cannot create ________ assign groups

  • It is not _________ to create randomly assigned groups


Pretest-Posttest Non-Equivalent Control-Group Design


Pretest-Posttest Nonequivalent Control-Group Design

  • Definition: A quasi-experimental design in which behavior in two _______________groups is measured pre and post-IV

  • No random __________ and ___________

  • Because you measure behavior before treatment you can evaluate group equivalence - it reduces the threat of _______________

    • e.g., Effects of Flexible vs. fixed work hours on productivity in two factories

    • e.g., Effects of Home-based vs. School-based treatment on problem behavior


Posttest Only (Static) Group Design


Posttest Only (Static) Group Design

  • No random selection and assignment

  • 2 __________________, e.g., children in 2 clinics

  • Groups should be ______

  • Susceptible to internal validity threats, e.g., assignment bias (selection threat) - group assignment is _______

    • Example: effects of peer tutoring in two classrooms


Time-Series Design

  • Definition: A quasi experimental design in which behavior in one group of participants is measured across time _______________ an IV is implemented.

  • ___________________ control for multiple threats to internal validity

  • Allows you to evaluate _________ across time

  • Called ___________________ when the IV is not created by the experimenter

  • Called a time series design with _______________if the treatment is repeatedly presented across multiple groups.


Intact Group of Participants

Measurement

of DV

Measurement

of DV

Measurement

of DV

Measurement

of DV

Measurement

of DV

Experimental

Condition

____________ Design


Time-Series Design

Example: Effects of anti-smoking campaign on smoking frequency

No ______ group – hard to tell if campaign was effective

Time Series – Effect was just part of periodic ____________

Time Series – Effect was just part of downward ________

Time Series – Effect occurs only after ____________


Group at

Time 1

(e.g., 10 yrs)

Group at

Time 1

(e.g., 20 yrs)

Group at

Time 1

(e.g., 40 yrs)

Developmental Research Designs – study age-related changes in behavior

Longitudinal design

  • Measuring a variable in individuals over an ___________________

  • Like a time-series design with no _______________

  • Can determine how an individual _________

  • No cohort effects

  • Very _____________, expensive

  • Problems with _____, ________


One-Group Pretest-Posttest Design

1 naturally occurring group

Pretest and postest


One Group Pretest-Posttest Design

  • Observation made in ____ group before and after treatment

  • No attempt is made to control for many threats to ________________


  • Login