Question 1

______ occur(s) when participants choose not to complete a study.

Accepted Answer

Attrition refers to the loss of participants during a study, either due to dropping out or being unable to continue for various reasons. This can significantly impact the validity and reliability of a study's findings, as it may introduce biases or alter the representativeness of the sample population. Therefore, it is important to address and monitor attrition rates in research studies.

Question 2

When participants are randomly assigned to levels of the independent variable in an experiment to control for individual differences as an extraneous variable this is called ______.

Accepted Answer

Random assignment helps to ensure that individual differences are evenly distributed across the different levels of the independent variable, which allows researchers to more confidently draw conclusions about the effects of the independent variable on the dependent variable.

Question 3

______ occur when participants are tested more than once in a study with early testing affecting later testing.

Accepted Answer

Testing effects, also known as practice effects or repeated testing effects, occur when participants' performance on a task changes as a result of being tested more than once. This can happen because participants become familiar with the task and more efficient at completing it with repeated exposure. However, this improvement can also affect later testing and can lead to a confound in the results of the study.

Question 4

A non-equivalent pretest-posttest design contains a control group that ______.

Accepted Answer

A non-equivalent pretest-posttest design involves a control group that has not been randomly assigned, distinguishing it from experimental designs where random assignment is a key feature. This lack of random assignment can introduce selection bias, making it harder to attribute differences in outcomes to the intervention alone.

Question 5

An example of a quasi-experiment is ______.

Accepted Answer

Quasi-experiments involve comparing groups that are not randomly assigned. In option A, participants are grouped based on a pre-existing characteristic (handedness), making it a quasi-experiment.

Question 6

Of the following, ______ are not considered a source of bias problematic in pretest-posttest designs.

Accepted Answer

Placebo effects are not typically considered a source of bias in pretest-posttest designs, as they would affect both the pretest and posttest equally. History effects refer to outside events that may affect the outcome being measured, testing effects refer to the influence of taking the pretest on the posttest results, and group differences refer to differences between the groups being compared that may affect the outcome.

Question 7

The difference between an interrupted time series design and an equivalent time series design is that the interrupted time series design includes a ______ event, while a noninterrupted time series design includes a ______ treatment.

Accepted Answer

An interrupted time series design includes a naturally occurring event, such as a policy change or a natural disaster, that interrupts the time series data. In contrast, an equivalent time series design includes a noninterrupted treatment that is implemented by the researcher, such as a new therapy or intervention.

Question 8

The Solomon four-group design allows a researcher to measure ______.

Accepted Answer

The Solomon four-group design allows a researcher to measure the effect of taking the pretest on the scores on the posttest. This design involves four groups of participants: two groups that receive a pretest before the experimental treatment, and two groups that do not receive a pretest. This design helps to control for the potential confounding variable of pretest sensitization, which refers to the idea that taking a pretest may sensitize participants to the experimental treatment and affect their scores on the posttest. By comparing the posttest scores of the two groups that received the pretest to the posttest scores of the two groups that did not receive a pretest, researchers can determine if pretest sensitization had an effect on the results.

Question 9

A time series design where the "treatment" is implemented by the researcher is called a(n) ______.

Accepted Answer

A noninterrupted time series design involves a single group that is measured repeatedly over time, with the treatment being implemented at a specific point in time by the researcher. This allows for a comparison of data before and after the treatment to determine its effectiveness. The other options either involve a control group or a posttest only design, which do not fit the description of a time series with a treatment implemented by the researcher.

Question 10

In a(n) ______ design, the researcher considers the difference between the pretest and posttest scores across the control and experimental groups.

Accepted Answer

In a nonequivalent groups design, the researcher compares the outcomes (e.g., pretest and posttest scores) of groups that are not randomly assigned, allowing for the examination of differences across control and experimental groups.

Question 11

______ would help control for bias in a pretest-posttest design.

Accepted Answer

By including a control group that does not receive the treatment, any changes observed in the treatment group can be compared to changes in the control group. This helps to control for bias, such as placebo effects or history effects, that may otherwise influence the results of a pretest-posttest design. Increasing the amount of time between the pretest and posttest, using fewer subjects, or using the posttest scores as the dependent variable do not specifically address bias in the design.

Question 12

Quasi-experiments are not experiments because they lack ______.

Accepted Answer

Quasi-experiments are not true experiments because they lack random assignment of participants to groups, which is a crucial element in controlling for extraneous variables and establishing causality. However, they may still have a comparison group, a dependent variable, and pre- and posttest measurements.

Question 13

A ______ is a type of research design where behavior is measured both before and after a treatment or condition is implemented.

Accepted Answer

A pretest-posttest design involves measuring behavior before and after a treatment or condition is implemented, making it the correct choice. The Solomon four-group design includes additional control groups, while a quasi-design lacks a true control group. A time-series design involves measuring behavior at multiple time points but may not involve a treatment or condition.

Question 14

In terms of the way data are analyzed, a quasi-experiment is most like ______ research design.

Accepted Answer

Quasi-experiments and experiments are similar in that they involve the manipulation of an independent variable and the measurement of a dependent variable. However, quasi-experiments lack random assignment of participants to conditions, which is a key feature of experimental designs. Therefore, quasi-experiments are considered weaker than true experiments but still closer in design to experiments than to correlational, case study, or phenomenological research.

Question 15

Pretest-posttest designs are quasi-experiments when they do not contain a ______.

Accepted Answer

Quasi-experiments lack control over the assignment of participants to groups, so the absence of a randomly assigned control group is a characteristic of this type of design. Pretest-posttest designs include measurements taken before and after a treatment or intervention, so they do contain dependent variables and independent variables. Confounding variables can also be present in quasi-experiments, but their absence is not a defining characteristic of pretest-posttest designs.

Question 16

A study was done in Pueblo, CO, to compare the pattern of heart attack rates across the year before and the year after a public smoking ban had been enacted. The researchers who conducted this study used a(n) ______ design.

Accepted Answer

The interrupted time series design is appropriate for this study because the researchers are comparing the heart attack rates before and after a specific event - the enactment of a public smoking ban. The other designs listed do not account for this specific event and would not be appropriate for this study.

Question 17

The Solomon four-group design is a pretest-posttest design where ______.

Accepted Answer

In the Solomon four-group design, there are two experimental and control groups. One group takes the pretest and then receives the treatment, while the other group does not take the pretest but still receives the treatment. This allows researchers to account for the potential confounding effects of pretesting on the outcome of the study. The other two groups act as a control, with one taking the posttest only and the other taking both the pretest and posttest.

Question 18

A time series design where the "treatment" is an independent event, such as a historical event is called a(n) ______.

Accepted Answer

An interrupted time series design is where the "treatment" is an independent event that interrupts the normal pattern of data collection. This type of design is useful for evaluating the impact of historical events or policy changes. The other options do not fit this description.

Question 19

Time series designs are pretest-posttest designs that ______.

Accepted Answer

Time series designs involve measuring a pattern of scores over time, both before and after a treatment or intervention is introduced. This is different from a pretest-posttest design, which typically only measures scores before and after the treatment. Time series designs do not necessarily include a control group or groups that do not take either the pretest or posttest.

Question 20

Of the following, ______ might be a reason a researcher would use a quasi-experiment.

Accepted Answer

If age is the variable of interest, it may not be ethical or feasible to randomly assign participants to different age groups in an experiment. Therefore, a quasi-experiment may be the best option to study the relationship between age and the outcome variable.

Quiz 14: More About Quasi-Experiments