module 2 study designs Flashcards
randomized controlled trials
randomization control manipulation (independent variables) - a true experiment, conveys causality
quasi-experimental
one element of true experiment lacking
- usually randomization
– may be d/t ethical reasons or feasibility
Less control over external bias and random error
non-experimental
descriptive
inferential
descriptive studies
gather and describe in numbers
- collect info to portray in characteristics, circumstances, or frequencies of occurrence.
inferential studies
cohort
case-control
cross-sectional
-observational studies
cross sectional
inferential study
collection of data on study participants current outcome status and exposure status at one point in time
- provide indirect evidence about time order, which variable occurred first
case controlled
inferential study
collection of data about study participants current outcome status and past exposure status
longitudinal (prospective/cohort)
inferential study
collect data at more than one point in time, follows participants forward
- clearly determines cause before outcome, provides stronger evidence, but still could have alternate explanations
2 types of statistics
descriptive
inferential
descriptive statistics
numbers and graphical summaries
- describe characteristics of population sample
inferential statistics
statistical techniques - chi-square test - t- test - ANOVA Allow conclusions about relationships among different variables
Explanatory studies (inferential statistics)
purpose: elucidating relationships among variables
- observational data
questions answered usually based on est. theories
prediction and control studies
purpose: determine which variables are predictive of other variables and determine causality
- quasi
- experimental
4 main purposes of empirical research
description
exploration
prediction
control
