Section 1 - Analysis and Critique

Summary of Core Research Attributes

Primary Research

The direct collection of original data by researchers to answer a specific research question.

Independent Variable

The predictor or manipulated variable that the researcher controls or assigns

Dependent Variable

The outcome or response variable that is measured to assess the effect of the independent variable.

Null Hypothesis

No difference or relationship exists between the independent and dependent variables

Secondary Research

Summarizes, evaluates, and synthesizes findings from multiple primary research studies to describe the overall state of knowledge on a topic.

Case Study

A detailed observation of a single individual or event, often involving rare diseases, injuries, or unique circumstances.

Case Series

Expands on a case study by observing multiple similar cases, often matched by key characteristics

Cohort Study

Follows a group (or multiple groups) over time to examine relationships between exposures and outcomes.

Randomized Controlled Trial (RCT)

intervention study where researchers control the allocation of treatments and the study environment

Placebo

Non-active treatment designed to be indistinguishable from the real intervention

Blinding

Reduces bias by limiting knowledge of treatment assigned

Single-blind (subject)

Participants do not know which treatment they receive

Single-blind (observer)

Researchers do not know treatment assignment

Double-blind

Neither participants nor researchers know assignments

Open-label

Both participants and researchers are aware of treatments

Gold Standard Design

The randomized, double-blind, placebo-controlled, crossover design is considered the highest standard in experimental research

Association

Two variables are related, but one does not necessarily cause the other

Causation

A change in one variable directly produces a change in another

Anecdote

A personal story or observation based on limited experience rather than systematic research

Narrative Review

Expert-selected summary of studies, flexible and interpretive, more susceptible to author bias

Systematic Review

Uses predefined transparent methods, comprehensive and unbiased

Meta-Analysis

A subtype of systematic review, applies statistical weighting based on sample size and effect size, produces a quantitative summary conclusion

Ethical and Practical Considerations in Study Design

Some research questions cannot ethically be studied using RCTs, such as inducing disease or harmful behaviors. In these cases, observational designs like cohort studies are more appropriate and ethical.

Retrospective study

Examines existing data to identify exposures and outcomes from the past.

Prospective Study

Identifies participants without the outcome and follow them over time to see who develops the outcome

Cross-sectional Study

Assesses both exposure(s) and outcome(s) simultaneously in a population at one point in time.

Parallel Study Design

Participants are randomly assigned to one of two (or more) intervention groups and followed in parallel.

Cross-Over Study Design

Participants receive two (or more) interventions in a random order, with a washout period in between. Subjects may start with Intervention A or Intervention B (randomized).

Pre-Post Study Design

Participants are measured before the intervention (baseline) and after the intervention to assess change.

Peer Review

A process by which experts in a field of study independently evaluate a manuscript for quality.