The independent groups design is an experimental design whereby two groups are exposed to different experimental conditions. Usually half of the participants are assigned to the experimental group where they are exposed to a condition where the independent variable is manipulated.
Why do we use independent groups?
Each group contains different subjects and there is no meaningful way to pair them. Independent groups are more common in hypothesis testing. For example, the following experiments use independent samples: A medication trial has a control group and a treatment group that contain different subjects.
What are the weaknesses of an independent groups design?
Independent Measures:
Con: More people are needed than with the repeated measures design (i.e., more time consuming). Pro: Avoids order effects (such as practice or fatigue) as people participate in one condition only.
What are strengths in independent groups in psychology?
A strength of the independent measures design is that because participants only take part in one condition participants are less likely to become border or practiced and therefore the experiment is more likely to measure natural real-life behaviour.
What is the main difference between independent groups and within groups designs?
In a within groups design they are exposed to all levels, in an independent groups design they are only exposed to one level. Participants are exposed to all the levels of an independent variable at roughly the same time, and a single attitudinal or behavioral preference is the dependent variable.
What are the advantages of repeated measures design?
The primary strengths of the repeated measures design is that it makes an experiment more efficient and helps keep the variability low. This helps to keep the validity of the results higher, while still allowing for smaller than usual subject groups.
Why would you choose to use an independent samples design or a paired samples repeated measures design?
The advantage of this is that individual differences between participants are removed as a potential confounding variable. Repeated measures also requires fewer participants, as data from all conditions is from the same group of participants.
What is an advantage of using a matched pair or dependent samples design over an independent samples design?
The major advantage of choosing a repeated-measures design (and therefore, running a dependent t-test) is that you get to eliminate the individual differences that occur between participants – the concept that no two people are the same – and this increases the power of the test.
What is a strength of an independent samples design?
Advantage – Reduces demand characteristics: An independent samples design makes it less likely that participants will guess the hypothesis of the experiment. If participants complete the experiment twice, they might guess the purpose of the experiment, and change their behavior accordingly.
What are the advantages of matched pairs design?
Differences between the group means can no longer be explained by differences in age or gender of the participants. The primary advantage of the matched pairs design is to use experimental control to reduce one or more sources of error variability. One limitation of this design can be the availability of participants.
How is using a matched pair design an improvement on an independent groups design?
Suggested Answer: Using a matched-pairs design would improve this study as it would reduce individual/participant differences. In an independent groups design, it could be participant variables that reduce the post-therapy scores in Group 2 and not the therapy itself.
What is the major advantage of a within participants design?
Perhaps the most important advantage of within-subject designs is that they make it less likely that a real difference that exists between your conditions will stay undetected or be covered by random noise. Individual participants bring in to the test their own history, background knowledge, and context.
What are two disadvantages of within groups designs?
Fatigue is another potential drawback of using a within-subject design. Participants may become exhausted, bored, or less motivated after taking part in multiple treatments or tests. Finally, performance on subsequent tests can also be affected by practice effects.
What are some potential disadvantages of a within groups design?
Within-group designs may not be possible or practical for studying certain topics or problems. Within-groups designs may suffer from demand characteristics. Within-groups designs may suffer from carryover effects. Within-groups designs may suffer from practice effects.
