Research Methods: Chapters 10 Flashcards
What type of studies are for causal claims?
What type of studies are for frequency & association claims?
- Experimental studies are for causal claims.
- Non-experimental studies are for frequency & association claims.
What does “experiment” mean in psychology?
Researchers manipulated at least one variable and measured another.
What are manipulated, measured and control variables?
- Manipulated variables are controlled (independent variable).
- Measured variables are either self-reported, observed, or physiologically reported, showing how they react to the manipulated variable (dependent variable).
- Control variables are variables that experimenters keep the levels the same for all participants.
What is a condition in an experimental study?
Conditions, also known as “levels,” are the different categories or values that the variable can take, which are manipulated or changed by the researcher to see their effect on the dependent variable.
What role do variables play in experimental studies?
Independent variables are manipulated (cause) and then the reaction of the dependent variables are measured (effect).
What is the definition of and the difference between comparison and control groups?
- Control groups are a group in a study that serves as a baseline for comparison, consisting of participants who do not receive the experimental treatment, allowing researchers to isolate the effects of the independent variable.
- Comparison groups are a group in a study used to compare against an experimental group, allowing researchers to assess the effects of a specific intervention or variable.
- The difference between these two groups is that the control groups receive no treatment, whereas the comparison group receives a different treatment. (placebo vs alternate type of comparative treatment).
What is randomization/random assignment?
Researchers assign participants to different experimental groups (like treatment or control) randomly, ensuring each participant has an equal chance of being in any group, which helps minimize bias and strengthens the validity of causal inferences.
Not random sampling
What are the types of experimental designs, and explain each.
- Between-Subject Design: One group of participants in one condition and another group in a different condition. Participants experience only on condition.
- Within-Subject Design: Everyone in the study experiences all of the conditions.
- Single-Subject Design: each participant serves as their control, focusing on repeated measurements of a behavior or outcome to evaluate the effectiveness of an intervention or treatment.
What are the types of Between-Subject Designs, and explain what they are.
- Randomized Two-Group Design: A research method where participants are randomly assigned to either an experimental group (receiving a treatment) or a control group (not receiving the treatment), allowing researchers to compare outcomes and determine the effect of the treatment.
- Randomized Multi-Group Design: A research method where participants are assigned randomly to multiple groups (three or more) to compare the effects of different levels of an independent variable, ensuring that any differences observed are likely due to the variable being manipulated, not pre-existing differences between groups.
- Matched Pair-Group Design: Researchers pair participants based on shared characteristics, then randomly assign one member of each pair to a treatment group and the other to a control group to control for extraneous variables
- Matched Multi-Group Design: An experimental design where participants are matched on a variable that might affect the dependent variable, then split into two or more groups, aiming to create equivalent groups and control for individual differences
What are order effects, and what are some examples?
Order effects are the potential for a particular threat to internal validity. Sometimes, being exposed to one condition changes how participants react to the other condition. (Within-Group Design)
- Practice effects (fatigue): A long sequence might lead participants to get better at the task, or to get tired or bored at the end.
- Carryover effects: Some form of contamination carries over from one condition to the next.
Explain counterbalancing.
Counterbalancing is when researchers present the levels of the independent variable to participants in different sequences.
What are treatment and placebo groups?
- Treatment groups are the group of subjects that receive the experimental treatment or intervention being studied (independent variable).
- Placebo groups are groups that receive a treatment that appears to be active but is actually inert (control group)
Control groups are not always placebo groups, but placebo groups are a type of control group
Explain confounds and design confounds.
- Confounds are factors that are not part of the study but can affect the outcome, making it difficult to determine if the independent variable is truly causing the observed changes in the dependent variable or if there is an alternative explanation.
- Design confounds occur when an experiment is poorly designed, leading to an alternative explanation for the results, making it difficult to determine if the independent variable caused the observed effect.
What is systematic and unsystematic variability?
- Systematic variability is predictable differences or patterns in data that are related to specific variables or factors, rather than random fluctuations.
- Unsystematic variability is the random or haphazard fluctuations in data or performance that are not attributable to a specific, identifiable cause, but rather to random or unpredictable factors.
What are selection effects?
Selection effect occur when the way a sample is chosen for a study leads to a non-representative group, potentially skewing the results and making them ungeneralizable to the broader population.
What are matched groups?
Participants are paired based on shared characteristics, and one member of each pair is randomly assigned to either the experimental or control group, aiming to control for confounding variables and ensure groups are comparable.
Explain posttest-only design and pretest/posttest design.
Between-Groups Designs
- Posttest-Only Design: Participants are randomly assigned to independent variable groups and are tested on the dependent variable.
- Pretest/Posttest Design: Participants are randomly assigned to at least two different groups and are tested on the key dependent variable twice - once before and once after exposure to the independent variable.
What are repeated-measures design and concurrent-measures design?
- Repeated-Measures Design: A type of within-group design in which participants are measured on a dependent variable more than once, after exposure to each level of the independent variable.
- Concurrent-Measures Design: Participants are exposed to all levels of an independent variable at roughly the same time, and a single attitudinal or behavioral preference is the dependent variable.
What are demand characteristics?
Cues that might indicate the study’s purpose to participants, potentially influencing their behavior or responses to align with what they perceive as expected
What is a manipulation check?
An extra dependent variable that researchers can insert into an experiment to convince them that their experimental manipulation worked.
