Physics and Math 11 Reasoning About the Design and Execution of Research

Physics and Math 11: Reasoning About the Design and Execution of Research The Scientific Method Initial steps: Focus on formulating a hypothesis. Intermediate steps: Focus on testing that hypothesis. Final steps: Provide results for further testing of the hypothesis. FINER Method: Assesses the value of a research question on the basis of whether or not it is feasible, interesting, novel, ethical, and relevant. Ethics Medical Ethics: 4 tenets: beneficence, nonmaleficence, respect for patient autonomy, and justice Research Ethics: Respect for persons, justice, beneficence. Must have equipoise – a lack of knowledge about which arm of research study is better for the subject Research in the Real World Populations: All of the individuals who share a set of characteristics. Population data are called parameters. Samples: A subset of a population that are used to estimate population data. Sample data are called statistics. Internal Validity: If the outcome of the research is that the DV has been affected as a result of manipulating the IV. Any confounding variables have been controlled for. External Validity: Refers to the ability of a study to be generalized to the population that it describes. Within-Subject Controls for individual variations in a measurement by Design: comparing the scores of a subject in one condition to the scores of the same subject in other conditions. So the subject serves as its own control. Statistical Refers to the low likelihood of the experimental findings Significance: being due to chance. Clinical Refers to the usefulness or importance of experimental Significance: findings to patient care or patient outcomes. Basic Science Research Occurs in the lab, not in human subjects. Basic science research is often the best type for demonstrating causality because the experimenter has the highest degree of control over the experimental conditions. Variables: Independent Variable: Manipulated Dependent Variable: Observe for change. Controls: Positive Controls: Ensure that a change in the dependent variable occurs when expected. Negative Controls: Ensure that no change in the dependent variable occurs when none is expected. Accuracy The quality of approximating the true value. (Validity): Precision The quality of being consistent in approximations. (Reliability): Human Subject Research Human subjects research is subject to ethical constraints that are generally absent in basic science research. Causal conclusions are harder to determine because circumstances are harder to control. Much of human subject research is observational. Cohort Studies: Record exposures throughout time and then assess the rate of a certain outcome. Cross-sectional Assess both exposure and outcome at the same point in Studies: time. Case-Control Assess outcome status and then assess for exposure Studies: history. Hill’s Criteria: Used to determine if causality can be supported. The criteria include temporality (necessary for causality), strength, dose-response, relationships, consistency, plausibility etc. Bias: Selection Bias: The sample differs from the population. Detection Bias: Arises from educated professionals using their knowledge in an inconsistent way by searching for an outcome disproportionately in certain populations. Hawthorne Effect: Behavior of subjects is altered simply by knowing that they are being studied. Social Desirability Bias: A type of response bias that is the tendency of survey respondents to answer questions in a manner that will be viewed favorably by others. Placebo Effect: Results are influenced by the fact that the subjects are aware they are or are not in the control group. Confounding An extraneous variable that relates to BOTH the Variable: dependent and independent variables. Mediating The means by which the IV affects the DV. It is the Variable: “middleman” between the IV and DV. Moderating Influences the already established relationship between Variable: the IV and DV. Moderators affect the strength of the relationship between the two variables.