Analysis & Critique Exam 1

Primary articles

actual evidence; a firsthand report of the data was collected

Types of primary research

experiments and observational studies

Secondary articles

summarize many primary articles

Purpose of experimental research

to investigate cause & effect relationships by manipulating independent variables to determine their affect on dependent variables

Features of experimental research

establish causality, control extraneous variables, use control groups & randomization, & not very generalizable

Observational research

observe, analyze, & describe what exists, instead of manipulating variables

Features of observational research

investigate cause & effect relationships, however independent variables can’t be manipulated because it is something participants already have. Limited by a lack of control.

What is Peer Review?

A process where a group of people in a similar field of study independently evaluate a body of work.

Dependent variable

represents the output or effect

Independent variable

the intervention or predictor

Internal validity

technical soundness of a study

External validity

the generalizability of the results

Hawthorne Effect

notion that people change their behavior because they know you are watching

Placebo Effect

if given something you act different

John Henry Effect

you figure out what group you are in & if in the control group, you try harder

Case Study (Observational)

detailed report and outcome of an individual person; subjects matched with control conditions

Strengths of a case study

• identifies unique attributes of uncommon conditions

• may provide initial data about an unknown condition

Weakness of a case study

have a very select generalizability

Case control/case-series study (observational)

two groups differing in outcome are compared on the basis of a causal attribute; subjects are matched with control conditon

Strengths of case control/case series study

• correlations can lead to meaningful interventions

• do no harm

Weakness of case control/case series study

can’t always gather causation

Cohort study (observational)

populations with distinct characteristics are tracked for development of some measurable outcome

True experiment

best type of design because it controls threats to internal validity

Parallel experimental design

each subject receives only one treatment conditon

Cross-over experimental design

each subject receives every treatment conditon

Pre/post experimental design

• weak experiment design & lack of control

• no randomization

• significant threats to internal & external validity

Quasi experimental design

lack random selection or assignment and lack control of true experimental design

Randomization

random assignment into groups

Single blinding

subjects are unaware of treatment condition received

Double blinding

neither subject or researcher are aware of treatment conditions received

Observer blinding

the researcher is unaware of the treatment condition received

Placebo-controlled

Placebos are necessary for blinding and provide a foundation for comparison with the treatment group

What is the best type of study?

A randomized, double-blind, placebo controlled crossover study

Secondary Research (Review) Articles

contain data or info that was originally reported by someone other than who collected it

Systematic Review Articles

authors non-biasedly summarize research articles to answer their research question or summarize current knowledge of a subject

Meta-analyses Review Articles

weigh findings from primary sources and reach a statistical conclusion

Narrative Review Articles

summarize original research articles regarding current knowledge of one aspect of their research

Strengths of Review Articles

• easy to interpret

• limited bias

• more generalizable

Weaknesses of Review Articles

• replicate and magnify flaws

• Not quick reads