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research and design
What is the third-variable problem?
The third-variable problem refers to a situation in research where a correlation between two variables may be influenced by a third, unexamined variable, leading to misleading conclusions about their relationship.
what are the differences between internal and external validity?
Internal validity focuses on whether a study accurately reflects a true cause-and-effect relationship within the context of the study itself, while external validity examines the extent to which findings can be generalized to other populations, settings, or situations.
What is random assignment and what are the advantages and disadvantages of using it?
Random assignment in research refers to randomly placing participants into different groups (e.g., experimental and control) to ensure that each participant has an equal chance of being assigned to any group, minimizing bias and allowing for stronger inferences about cause-and-effect.
Advantages:
Reduced Bias:
Random assignment helps to eliminate systematic differences between groups at the outset, making the groups more comparable.
Improved Internal Validity:
By minimizing bias, random assignment allows for stronger causal conclusions, as any observed differences between groups are more likely due to the treatment and not pre-existing differences.
what are the disadvantages to using more than 2 treatment conditions in a within-subjects design?
Using more than two treatment conditions in a within-subjects design can introduce complex carryover effects, fatigue, potential for practice effects, and increased study duration
What is a confounding variable (CV)?
a cofounding variable are EVs that systematically change with and affect the IV or DV. Confounding variables (CVs) are extraneous variables that correlate with both the independent variable (IV) and dependent variable (DV), potentially leading to misleading results in an experiment.
What are the 5 time-related threats to internal validity are and what they mean: history, maturation, instrumentation, testing effects, regression toward the mean?
1. History- events that happen outside of lab setting
2. maturation- effects related to aging
3. aggression to the mean- extreme score are hard to maintain and over time move more toward average
4. testing effects- effects from previous tests carrying over into future tests
5. instrumentation- changes in measurement standards, scale not working correctly/giving different results each time
What does process research mean? (how it relates to placebo effect)
Process research- wanting to isolate active portion of a treatment. Outcome and process are different. Placebo effect is the simple knowledge of treatment is enough to produce a psychological effect, doesn’t last that long
How does holding a variable constant affects external and internal validity
In psychological research, holding a variable constant strengthens internal validity by reducing the influence of confounding factors, but may limit external validity by creating a less realistic and generalizable experimental context.
what are the disadvantages of a between-subjects design?
it requires more participants, *individual differences can be CVs (threaten internal validity), prone to assignment bias, less statistically powerful
What are manipulation checks are and why they are performed?
a way to see if the manipulation worked, the purpose is to make sure that the IV was manipulated correctly. Manipulation checks are assessments conducted during experiments to verify if the independent variable (IV) was effectively manipulated. They help ensure that the experimental conditions are perceived as intended by participants, thereby enhancing the validity of the study's findings.
what are the advantages of using a within-subjects design?
requires less participants, no individual differences, more statistically powerful. It allows each participant to serve as their own control, which reduces variability and enhances the sensitivity of the experiment. This design can lead to more reliable results while requiring fewer resources.
what are the advantages of using a field study?
Field studies allow researchers to observe behavior in natural settings, increasing ecological validity. They often yield more generalizable results compared to laboratory studies by capturing real-world dynamics.
what are the differences between validity and reliability?
reliability: Being able to get similar results on more than more occasion. Validity: A test/study accurately measures what is claims to
what are the differences between independent and dependent variables?
the independent variable is manipulated by the researcher to observe its effect on the dependent variable, which is the outcome or measure being studied. The independent variable is the cause. Its value is independent of other variables in your study. The dependent variable is the effect. Its value depends on changes in the independent variable
What is the negativistic subject role?
participants who deliberately try to sabotage a study by acting contrary to the expected outcomes or hypothesis, often by giving deceptive or unexpected responses.
reliability: Being able to get similar results on more than more occasion. Validity: A test/study accurately measures what is claims to
In research and psychology, reliability refers to the consistency of a measure, while validity refers to the accuracy of a measure in assessing what it claims to.
what are the differences between between-subjects designs and within-subjects designs?
between subject design uses different groups of people for each level of the IV, within subject design uses only one group that is exposed to all levels of the IV
describe the the differences between a research strategy and a research design
A research design is the overall plan for how you will conduct your research, addressing questions like what methods you will use, what data you will collect, and how you will analyze it. A research strategy, on the other hand, is a more general plan or approach that helps you organize your thoughts and efforts to conduct research systematically and on schedule
what are the desired levels of variance between-subjects versus within-subjects?
Between- conditions variance: good variance shows one condition differs from another
Within-conditions variance: bad variance, error variance, shows people and or conditions within the same group are not similar enough/standardized
*within subject design has less bad variance, assuming you only have two conditions.
Within-subjects designs aim for minimal variance among participants across conditions, enhancing sensitivity to differences. In contrast, between-subjects designs require significant variance between groups to identify effects, as each participant only experiences one condition.
What is resentful demoralization?
one group gives up after finding group status. and perceiving that they are at a disadvantage compared to another group, leading to decreased motivation and performance.
what are the differences in required number of participants in a within-subjects versus a between-subjects design?
within subject design requires less participants with no individual differences, and between subject design requires more participants to account for individual differences and ensure statistical power.
describe the number of scores obtained from participants in a between-subjects versus a within-subjects design
In a between-subjects design, each participant provides one score, corresponding to their experience in only one condition, while in a within-subjects design, each participant contributes multiple scores, one for each condition they experience.
Between-subjects (also called independent measures or between-groups) design:
What does assignment bias mean?
In psychological research, "assignment bias" occurs when participants are assigned to different experimental groups in a way that systematically creates differences in characteristics between those groups, leading to skewed results
Describe the two elements that are unique to the experimental research strategy
The two elements unique to the experimental research strategy in psychology are manipulation of an independent variable and controlled conditions to minimize extraneous influences.
What are carry-over effects?
Carry-over effects refer to the influence that a previous treatment or condition has on subsequent treatments in a within-subjects design, potentially altering the results.
what are threats to internal and external validity
- the biggest threat to internal validity are CVs and EVs, the main threat to external validity are you want generalizability, threats include selection bias/sampling bias, biases w/college students, volunteer bias, holding constant, making the environment too artificial. Field study and simulation are a way to minimize this.
What are demand characteristics?
anything in the study that was not intended to be in there that might have an influence (involves procedures). Experimenter bias, participant reactivity. Participant reactivity is acting abnormally due to experimental setting.
How does a simulation study work?
are designed to replicate real-world scenarios in a controlled environment, allowing researchers to study behavior and responses without the ethical concerns of actual experimentation. Participants are placed in situations that mimic real-life conditions to gauge their reactions.
What is experimental realism?
Experimental realism is the extent to which situations created in social psychology experiments are real and impactful to participants.
what is the goal of an experimental research strategy?
The primary goal of an experimental research strategy in psychology is to establish a cause-and-effect relationship between two or more variables, allowing researchers to determine whether manipulating one variable (independent) leads to a change in another (dependent).
what are the differences between a placebo group and a no-treatment control group?
In research, a no-treatment control group receives no intervention whatsoever, while a placebo group receives an inactive treatment that looks similar to the experimental treatment.
What is restricted random assignment?
using randomization to assign participants to groups while imposing certain constraints to ensure specific group characteristics, such as equal group sizes or balanced characteristics, to improve the validity and comparability of experimental groups.
What is the directionality problem?
in psychology, the "directionality problem" arises when two variables are correlated, suggesting a possible causal relationship, but it's unclear which variable causes changes in the other. This makes it difficult to determine the true direction of the relationship, whether A causes B, or B causes A.
·What is a Latin square used for and does how it work – type of counterbalancing
time-related CVs are minimized through counterbalancing, but are also minimized by Latin square, partial square, complete counterbalancing
Counterbalancing refers to mixing up the order of conditions for different participants, more popular way to do this is using a Latin square or partial balancing, or complete counterbalancing which N refers to the number of conditions
What are the five research strategies are and what is involved in each?: descriptive, correlational, non-experimental, quasi-experimental, and experimental
1. Descriptive Research:
Goal: To accurately portray the characteristics of a population or phenomenon by observing and collecting data on variables like demographics, behaviors, or opinions without manipulating them.
Methods: Surveys, interviews, observations.
2. Correlational Research:
Goal:
To investigate the relationships between two or more variables by measuring them and determining how they are related, but without manipulating any variables.
Key aspect:
Identifying the strength and direction of the correlation (positive, negative, or no relationship).
3. Non-experimental Research:
Goal: To study phenomena as they naturally occur without actively manipulating any variables.
Examples: Case studies, observational research, archival data analysis.
4. Quasi-experimental Research:
Goal:
To examine the effect of an independent variable on a dependent variable, but without random assignment of participants to groups.
Key challenge:
Difficulty in isolating the causal relationship due to potential confounding variables.
5. Experimental Research:
Goal:
To establish a causal relationship between variables by manipulating an independent variable and observing its effect on a dependent variable while controlling for other factors through random assignment of participants to groups.
What is meant by diffusion in between-subjects designs?
diffusion is when the other group knows what the other group is getting, because information/treatment becomes shared among groups
What are order effects are and how do they affect results of studies?
Order effects refer to differences in participants' responses that result from the order in which experimental materials are presented to them.
Types of Order Effects:
Carryover effects: The effect of one treatment can influence responses to subsequent treatments.
Practice effects: Participants may perform better on later tasks due to increased familiarity or practice.
Fatigue/boredom effects: Participants may become fatigued or bored as they progress through the experiment, leading to decreased performance
What are the levels of an independent variable, and what does that means?
Independent Variable:
This is the factor that the researcher manipulates or changes to see if it affects something else. It is the potential cause in an experiment.
Levels (or Conditions):
These are the different categories, groupings, or values of the independent variable that are tested.
Example:
In an experiment testing whether different types of music affects memory, the independent variable could be "music genre", with the levels being "classical", "pop", or "rock".
Dependent Variable:
This is the factor that the researcher measures or observes to see if it is affected by the independent variable. It is the effect or outcome being studied
what problems are unique with between subject designs
- First problem: diffusion, when the other group knows what the other group is getting, information/treatment becomes shared among groups
- Second problem: Differential attrition- rates of dropouts between groups is unequal
- Third problem: compared equalization: groups demand equality
- Competitive/compensatory rivalry: one group tries to perform better
- Resentful demoralization: one group gives up after finding group status
What are EVs
any factor other than the IV and DV
what does level of IV mean
each level/condition
what are three types of CV
Environmental, Participant related, Time-related. These are variables that can influence the outcome of an experiment but are not the independent variable (IV) or dependent variable (DV). They can introduce bias or variability that affects the interpretation of results.
describe internal validity
relationship established between variables with NO possible alternative explanations
What the 5 time-related threats to internal validity are and what they mean: history, maturation, instrumentation, testing effects, regression toward the mean
1. History- events that happen outside of lab setting
2. maturation- effects related to aging
3. aggression to the mean- extreme score are hard to maintain and over time move more toward average
4. testing effects- effects from previous tests carrying over into future tests
5. instrumentation- changes in measurement standards, scale not working correctly/giving different results each time
variance for between subject design and within-subject design
Between- conditions variance: good variance shows one condition differs from another
Within-conditions variance: bad variance, error variance, shows people and or conditions within the same group are not similar enough/standardized
what are the methods for controlling CVs
1. Randomization- use an unbiased way to assign participants to groups( ex. Coin toss) *passive method
2. Holding constant- keeping one characteristic the same for all participants (ex. Gender,age)
3. Matching- ensuring similar amounts of different characteristics for each groups
why do order effects matter
Confounding Results: If the order of treatments affects the outcome, it becomes impossible to determine if the observed changes are due to the independent variable (what you're testing) or simply the order in which the conditions were presented.
Reduced Validity: Order effects can reduce the internal and external validity of a study because the results may not accurately reflect the true effect of the independent variable.
what does managing order effect
Randomization: Randomizing the order in which treatments are presented to participants can help control for order effects.
Counterbalancing: Counterbalancing involves systematically varying the order of treatments so that each treatment condition occurs in each position.
Statistical Analysis: Researchers can use statistical techniques to analyze the effects of order on the data.
how are time related CVs minimized
through counterbalancing, but are also minimized by Latin stquare,parial square, complete counterbalancing
what is the Purpose of Restricted Random Assignment
Balance groups: It aims to achieve balanced groups based on predetermined characteristics, which helps reduce potential bias and confounding variables.
Increase validity: By controlling for group imbalances, restricted randomization enhances the internal and external validity of experimental results.
Example: If a study is evaluating the effects of two different therapy approaches, restricted assignment could ensure an equal number of participants in each group, regardless of their pre-existing anxiety levels
external validity
- extent to which results apply outside the study context, how they may apply to the real world
internal validity
relationship established between variables with no possible of alternative explanations
