experiments Flashcards
What is the difference between aims and hypotheses?
Aims are broad, general goals of a study, while hypotheses are specific, testable predictions about the relationship between variables.
What is a directional hypothesis? When is it used?
A directional hypothesis predicts the direction of a relationship between variables (e.g., ‘increased study time leads to higher test scores’). Used when previous research or theory indicates a specific direction.
What is a non-directional hypothesis? When is it used?
A non-directional hypothesis states that there is a relationship between variables but doesn’t predict the direction (e.g., ‘There will be a relationship between study time and test scores’). Used when there is no clear expectation about the direction of the relationship.
What is the difference between a population and a sample?
A population is the entire group you’re interested in studying, while a sample is a smaller group selected from the population to represent it.
What is random sampling and when is it used?
Random Sampling is when every individual has an equal chance of being selected. It’s used when you want an unbiased, representative sample from a large or diverse population.
What are the strengths and limitations of random sampling?
Strengths: Reduces selection bias and increases generalizability. Limitations: Difficult to obtain and not always feasible with large or hard-to-reach populations.
What is systematic sampling and when is it used?
Systematic Sampling is when every nth person is chosen from a list. Used when you have a list of participants and want an evenly distributed sample.
What are the strengths and limitations of systematic sampling?
Strengths: Simple and easy to conduct, ensures an even spread. Limitations: Can introduce bias if there is a hidden pattern in the list.
What is stratified sampling and when is it used?
Stratified Sampling is when the population is divided into subgroups, and participants are randomly selected from each subgroup to ensure proportional representation. Used when key subgroups need to be represented proportionally.
What are the strengths and limitations of stratified sampling?
Strengths: Ensures subgroups are well-represented and reduces bias. Limitations: Can be complex and time-consuming, requires detailed knowledge of the population.
What is opportunity sampling and when is it used?
Opportunity Sampling is selecting participants who are available at the time. Used when time and resources are limited, and a quick, accessible sample is needed.
What are the strengths and limitations of opportunity sampling?
Strengths: Quick and easy to collect, convenient for the researcher. Limitations: High risk of bias, low generalizability to the population.
What is volunteer sampling and when is it used?
Volunteer Sampling is when participants self-select to take part in the study. Used when ethical considerations are important (e.g., informed consent) and quick access to participants is needed.
What are the strengths and limitations of volunteer sampling?
Strengths: Ethical, participants consent voluntarily, quick and easy to collect. Limitations: Biased sample (people with certain interests are more likely to volunteer), may not represent the broader population.
What are the aims of pilot studies?
Pilot studies are small-scale preliminary studies designed to test the feasibility, methods, and procedures of the main study. They help identify potential issues such as unclear instructions or inappropriate materials.
What is the repeated measures design and when is it used?
Repeated Measures design is when all participants experience all conditions of the experiment. Used when you want to reduce participant variables.
What are the strengths and limitations of repeated measures?
Strengths: Reduces participant variables. Limitations: Order effects (e.g., practice or fatigue effects) can impact results.
What is the independent groups design and when is it used?
Independent Groups design is when different participants are used for each condition of the experiment. Used when you want to avoid order effects and don’t need participants in all conditions.
What are the strengths and limitations of independent groups?
Strengths: No order effects. Limitations: Increased individual differences may affect the results.
What is the matched pairs design and when is it used?
Matched Pairs design is when participants are paired based on relevant variables and then randomly assigned to different conditions. Used when you want to control for individual differences but still need different conditions.
What are the strengths and limitations of matched pairs?
Strengths: Reduces participant variables compared to independent groups. Limitations: Matching participants perfectly is time-consuming and difficult.
What is a laboratory experiment?
A laboratory experiment is conducted in a controlled environment where the researcher manipulates the independent variable (IV) to observe its effect on the dependent variable (DV).
What are the strengths of laboratory experiments?
Strengths: High control over variables, allowing for cause-and-effect relationships to be established. High reliability due to controlled conditions.
What are the limitations of laboratory experiments?
Limitations: Low ecological validity (may not reflect real-life situations), participants may act unnaturally (demand characteristics).
What is a natural experiment?
A natural experiment occurs when the researcher studies the effect of an independent variable that occurs naturally, without manipulation, in real-world settings.
What are the strengths of natural experiments?
Strengths: High ecological validity, as it takes place in a natural setting. Can study variables that cannot be manipulated ethically or practically.
What are the limitations of natural experiments?
Limitations: Less control over extraneous variables, making it difficult to establish cause and effect. Limited generalizability due to the specific nature of the study.
What is a quasi-experiment?
A quasi-experiment is similar to an experiment but lacks random assignment of participants to conditions. The independent variable is still manipulated, but groups are pre-existing.
What are the strengths of quasi-experiments?
Strengths: Can be used when random assignment is not possible (e.g., studying age, gender). It provides real-world data in natural settings.
What are the limitations of quasi-experiments?
Limitations: Lack of random assignment can introduce bias and confounding variables, making it harder to establish causality.
What is a field experiment?
A field experiment takes place in a natural setting, and the researcher manipulates the independent variable in a real-world context, often without participants knowing they are part of a study.
What are the strengths of field experiments?
Strengths: High ecological validity because the study takes place in a natural setting. Participants behave naturally since they are unaware of the experiment.
What are the limitations of field experiments?
Limitations: Less control over extraneous variables, and ethical concerns may arise (e.g., informed consent). Difficult to replicate due to uncontrollable factors.
