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Behavioral science 1
| Question | Answer |
|---|---|
| the group being studied changes its behavior because they know they are being studied | hawthorne effect |
| researcher's believe that a treatment is effective and it changes the outcome of the tx | pygmalion effect |
| early detection is confused with increased survival. Seen with improved screening | lead time bias |
| occurs when 2 closely associated factors "confound" each other | confounding bias |
| subjects in different group are not treated the same | procedure bias |
| the teacher pays special attention and spends mroe time with one gruop versus the other | procedure bias |
| information is gathered at the wrong time i.e. using a survey to study a fatal disease | late look bias |
| solution to late look bias | stratify by severity |
| subjects are not representative of the general pupolation | sampling bias |
| knowledge of presence of disorder alters recall by subjects | recall bias |
| solution to recall bias | confirmation |
| nonrandom assignment to study group | selection bias |
| all sampling is from hospital pts | selection bias |
| loss to follow up | selection bias |
| ways to reduce bias | 1. blind studes 2. placebo responses 3. crossover studies (each subjects acts as own control to limit counfounding bias) 4. randomization to limit selection bias and confounding bias |
| increase statistical power by? | meta analysis |
| pools data and integrates results from several similar studies to reach a conclusion | meta analysis |
| observer bias | the investicgator's decision is affected by prior knowledge of exposure status |