| Feature | Reliability | Validity |
|---|---|---|
| Core Question | Are the results consistent? | Are we measuring what we intended? |
| Focus | Precision and repeatability of the measurement. | Accuracy and relevance to the hypothesis. |
| Threats | Random errors, environmental fluctuations. | Systematic bias, poor experimental design. |
High reliability means that if the experiment were repeated under the same conditions, the results would be nearly identical.
High validity means the experimental setup successfully isolated the independent variable's effect on the dependent variable.
Identify the Trend: Always look for the overall direction of the data (increasing, decreasing, or constant) before focusing on individual points.
Check the Units: Examiners often use different units (e.g., grams vs. kilograms) to test your attention to detail during interpretation.
Evaluate the Sample: If a question asks about the strength of a conclusion, check the sample size and the duration of the study.
Suggest Improvements: When asked to critique an experiment, look for uncontrolled variables or potential sources of human error mentioned in the description.