Study Designs

Randomized control trial

Researcher manipulated the indeoendant variable

Uses control and randomization to test cause and effcet reltationships

Probability

Posttest only control group

Random assignment

One group gets intervention, ome doesnt then both tested after

One group pretest posttest

One group tested nefore and after intervention

No control group, non probability 

Solomon four group design

four groups, some pretsted, some not to control for tetsing effects

Probability

Pre experimental deisgn

Has manipulation, but no control or randomization

Low internal validity 

Non probability 

Quasi experimental design

Researcher manipulates variable but no random assignment or full contro, group

Nonprobabiliuty 

Non RCT

2 or moer groups compared, but not randomly assigned

Nonprobability 

Descriptive survery

Collects data points to describe charcateristics or explore relationships

nonprobaility

Correlational study

Examines relationships between variables without manipulation

non probaility

Cross sectional study

Data collected at one point in time to compare groups

Non probability

Longitudianl study

Follows same participantsbover time to bserve a change

Usually non probability

Cohort study 

Follows a group sharing a common charcteristic to ibserve outcomes over time

Retrospective study

Looks back on existing data to examin relationships or outcomes

Non probability 

Ex post facto study

Explores cause and effect relationships after events occur, using existing data

Non pribability

Developmental study

Studies how variabkes chage ove time

Lomgitudinal and corss sectional studied

Prediction study

How well one variable can predict another

Non probability

Time series design

Repeated measures taken over tie vefore and after an inteverntion

After only design

Data only collected after inteverntion

No pretest

Non probab ility 

Systeamtic review

Rigorous, structreed review indeitfying and synthesizing all relevant studies on a topic

Meta analysis

Statistical combination of quantitative study results to produce a pooled estimate

Integrative rebiew

Combines qualitiative and qiantitiative research to identify patterns or gaps

Scoping review

Broadly maps literature to idenityf key concepys, gaps or trends

Meta synthesis

Synthesizes findgins from multiple qualitiative studies to interpret deeper meaning

Secondary analysis

Reusing data from prior research

Formative evaluation

Conducted during programd development to make improvements

Summative evaluation

Conduavted after a prgram completion to assess overall effectiveness

Quality improvement initiative 

Aims to improve care processes 

Not formal research so doesnt need ethics review