Prelude to Research Validity Flashcards
Introduction to Research Validity
- Research Hypothesis (RH): A research hypothesis is defined as a guess about the relationships between behaviors.
- Workflow for Testing a Research Hypothesis:
- Select and decide on a research design.
- Sample participants from the population of interest.
- Collect empirical data from the sampled participants.
- Statistically analyze the collected data.
- Formulate a final conclusion regarding whether or not the empirical results support the research hypothesis.
- Core Definition of Validity:
- Validity encompasses numerous specific types, definitions, and methodological procedures, but it fundamentally refers to accuracy or correctness.
- The ultimate goal of the research process is to ensure that the final conclusion drawn is valid.
The Four Major Types of Research Validity
- External Validity:
- Evaluates the extent to which research results can be accurately generalized to other participants, situations, and times.
- Internal Validity:
- Evaluates whether it is correct to give a causal interpretation to the relationship found between the variables or behaviors.
- Measurement Validity:
- Evaluates whether the operationalized variables and collected data accurately represent the specific behaviors intended to be studied.
- Statistical Conclusion Validity:
- Evaluates whether the statistical analysis produced the correct conclusion regarding whether or not there is a relationship between the variables or behaviors being studied.
External Validity
- Key Methodological Decisions Influencing External Validity:
- Participants: Selection of the specific individuals from whom data are collected.
- Stimuli and Tasks: Selection of the materials, interventions, and activities with which participants interact.
- Setting: Selection of the physical and contextual environment in which data collection occurs.
- Applicability and Generalizability:
- After a study is completed, analyzed, and reported (whether presented at an academic conference or published in a journal or textbook), researchers and practitioners must evaluate its applicability.
- External validity assesses applicability by determining whether the target participants, stimuli/tasks, and settings of a prospective application are sufficiently close to those used in the original research design.
Internal Validity
- Evaluation of Causal Claims:
- Testing a causal research hypothesis requires ruling out confounds (alternative hypotheses regarding what causes the observed outcome).
- Internal validity assesses whether the experimental design effectively eliminates these competing alternative hypotheses.
- Concrete Example of Internal Validity and Confounding:
- Experimental Setup: A researcher provides computer-based math practice to a sample of 4th graders and paper-based math practice to a sample of 2nd graders.
- Observed Finding: The 4th graders receiving computer-based practice score higher on a math test than the 2nd graders receiving paper-based practice.
- Causal Claim: The researcher asserts that computer-based math practice directly causes superior learning.
- Alternative Hypothesis (Confound): 4th graders are inherently more advanced in math than 2nd graders and would predictably score higher on a math test regardless of the practice medium used.
- Conclusion: The age/grade level confound invalidates the causal claim, demonstrating low internal validity.
Measurement Validity
- Scientific Empiricism and Data Collection:
- Scientific empiricism requires concrete data serving as measures of behavior.
- Primary procedures for collecting behavioral data:
- Observation: Systematically watching and recording participant behavior.
- Example 1: Recording the number of aggressive behaviors exhibited by a child during school recess.
- Example 2: Recording the number of items a participant successfully remembers from a list of 40 nouns.
- Self-Report: Directly asking participants to report on their own behaviors, beliefs, or opinions.
- Example 1: Asking participants, "Did you vote in the most recent ASUN election?"
- Example 2: Asking participants, "How often do you try to make a new friend?"
- Core Focus:
- Measurement validity focuses directly on the accuracy and correctness of these measurement procedures and the data they generate.
Statistical Conclusion Validity
- Data Analysis in Scientific Empiricism:
- Scientific empiricism demands data-based evidence, requiring rigorous analysis of collected data.
- Testing both associative and causal research hypotheses requires determining whether a statistical relationship exists between behaviors or variables.
- Core Evaluative Questions:
- Was the chosen data analysis procedure appropriate for the specific type of data collected and the research hypothesis being tested?
- Was the decision regarding whether a relationship exists between the variables mathematically and statistically accurate?
Research Validity Practice Scenarios and Solutions
Scenario Set 1:
- Scenario 1: "I don’t know that I should apply your results from college students to my teaching of 4th graders."
- Validity Type: External Validity
- Explanation: Evaluates whether findings from a specific sample (college students) generalize to a different population and setting (4th graders).
- Scenario 2: "Are you sure that it is the cognitive-behavior treatment that decreased the participants' depression and not just that these folks had someone who would listen to their problems?"
- Validity Type: Internal Validity
- Explanation: Challenges a causal claim by raising an alternative hypothesis/confound (having an attentive listener).
- Scenario 3: "Was the 'Beck Depression Inventory' a good choice for this study?"
- Validity Type: Measurement Validity
- Explanation: Evaluates whether a specific measurement tool (Beck Depression Inventory) accurately measures the intended construct (depression).
- Scenario 4: "Are you sure there really is a relationship between practice and performance, or is this finding a 'fluke'?"
- Validity Type: Statistical Conclusion Validity
- Explanation: Questions the correctness of the statistical decision regarding whether a true relationship exists between variables.
Scenario Set 2:
- Scenario 1: "I’m not sure it was practice that improved performance, since the group that had the practice also had more previous experience."
- Validity Type: Internal Validity
- Explanation: Identifies a confounding variable (previous experience) that provides an alternative explanation for the performance difference.
- Scenario 2: "If cognitive-behavior treatment works, as your study found, why have the other 20 studies all found that it didn’t work?"
- Validity Type: Statistical Conclusion Validity
- Explanation: Questions the accuracy of the statistical outcome by comparing it against a large body of contradictory statistical findings.
- Scenario 3: "I’m sure that your method works great in the laboratory, but what about here in the 'real world'?"
- Validity Type: External Validity
- Explanation: Evaluates whether findings obtained in a specific setting (a laboratory) generalize to practical real-world contexts.
- Scenario 4: "Is how many problems they tried really a good index of success? I’d rather look at how many they got correct."
- Validity Type: Measurement Validity
- Explanation: Questions whether the operationalized measure (number of problems attempted) accurately reflects the target variable (success).