Research Design and Analysis II Test 2
which statement best characterizes a between-subjects experimental design?
each participant is assigned to one condition of the experiment.
which of the following accurately defines diffusion?
elements of the treatment in one group have spread to another group
Results from a research study suggest that a stop-smoking program is very successful. However, the participants who volunteered for the study were all highly motivated to quit smoking and the researcher is concerned that the same results may not be obtained for smokers who are not as motivated. What kind of validating is being questioned?
external validity
the degrees to which your research results generalize beyond the specific characteristics of your study refers to
external validity
which of the following described a variable that exists in a study bit is not being directly examined?
extraneous
Name and explain the threats to internal and external validity. Why are each a threat to that validity?
history effects- he specific events which occur between the first and second measurement. maturation- the processes within subjects which act as a function of the passage of time. i.e. if the project lasts a few years, most participants may improve their performance regardless of treatment. Testing--the effects of taking a test on the outcomes of taking a second test. Instrumentation--the changes in the instrument, observers, or scorers which may produce changes in outcomes. Statistical regression--It is also known as regression to the mean. This threat is caused by the selection of subjects on the basis of extreme scores or characteristics. Give me forty worst students and I guarantee that they will show immediate improvement right after my treatment.
Which of the following is an option for limiting the variance within treatment conditions?
hold a participant variable constant
Which of the following maximizes the likelihood of a successful research result?
increase the difference between treatments and decrease the variance within treatments
When comparing means in a two-group design, which statistical analysis is most appropriate?
independent-measures t-test
For a between-subjects experiment, which of the following is a possible threat to internal validity?
individual differences that exist between treatments
In a between-subjects experiment, is the participants in one group have characteristics that are different from the participants in another group, then which of the following is threatened?
internal validity
a researcher measures mood for a group of participant who have listened to happy music for 20 minutes and for a second group who have listened to sad music for 20 minutes. If different mood scored are obtained for two groups, the researcher would like to conclude that music influence mood. However, the happy music group was tested in a room painted yellow and the sad music group was in a room painted dark brown and the researcher is concerned that the room color and not the music may influence mood scores. What kind of valid is being questioned?
internal validity
what aspect of a study is threatened if the participants are tested in one treatment condition at one time and then tested in a second treatment
internal validity
Holding a variable constant is a technique for removing one threat to ____, but it can limit the ____ of an experiment.
internal validity, external validity
Researchers often use simulation experiments in an attempt to obtain the ____ of an experiment and still keep much of the ____ of research conducted in the real world
internal validity, external validity
In an experiment, what is the purpose for manipulating the independent variable?
it helps establish the direction of the relationship and it helps eliminate the third variable problem.
A researcher exposes people to a stressful situation such as public speaking to examine the effect of stress on depressed mood. Why would the researcher also include a measure of stress?
it is a manipulation check
Which of the following is the primary limitation of a two-group design?
it may not provide a complete picture of the relationship between the variables/
Which of the following characteristics are necessary for an extraneous variable to become a confounding variable?
it must change systematically when the independent variable is changed
what is the purpose for using a control condition in an experiment?
it provides a baseline that can be used to evaluate the size of the treatment effect
Which of the following is a potential problem with holding a participant variable constant?
it threatens the external validity of the study/
Although field studies tend to have higher external validity than traditional laboratory studies. What risk do they tend to have?
lower internal validity
In an experiment comparing two treatments, the Researcher assigns participants to treatment conditions so that each condition has fifteen 7-yr-old children dn ten 8-yr-old children. For this study, what method is being used to control participant age?
matching
Which of the following is a limitation of using matching rather than random assignment to form groups in a between subjects experiment?
matching requires error due to participant differences
Which of the following accurately defines compensatory equalization?
one group demands the same benefits received by another group.
Which of the following accurately describes the scores in a between-subjects experiment?
only one score is obtained for each participant
An experiment includes a treatment condition, a no-treatment control, and a placebo control. Which two conditions should be compared to determine the size of the effect that is actually caused by the treatment?
placebo versus treatment
Which of the following does not guarantee that a specific participant variable will not become a confounding variable?
randomizing the variable across treatment
When comparing means in a single-factor multiple group design, which statistical analysis is most appropriate?
single-factor ANOVA
Research indicates the people who suffer from depression also tend to experience insomnia. However, it is unclear whether the depression causes insomnia or a lack of sleep causes depression. What problem is demonstrated by this example?
the directionality problem
a journal article that a new teaching strategy is very strategy is very effective for first-grade students. A teacher wonders if the same strategy would be effective for a class of third grade students. what is the teacher questioning?
the external validity of the report
How can sensitization threaten external validity of a study?
the results may be limited to individuals who have experienced a pretest.
Which of the following questions can be addressed with the descriptive strategy?
what is the average number of text messages that a typical adolescent send in a month?
Dr. Jones is interested in studying how indoor lighting can influence people's moods during the winter. A sample of 100 households is selected. Fifty of the homes are randomly assigned to the bright-light condition where Dr. Jones replaces all the lights with 100-watt bulbs. In the other 50 houses, all the lights are changed to 60-watt bulbs. After two months, Dr. Jones measures the level of depression for the people living in the houses. In this example, how many dependent variables are there?
1
If a between-subjects experiment produces 50 scores in treatment 1 and 50 scores in treatment 2, then how many participants were in the entire apartment?
100 participants
Applied research ( categories of research)
Studies individual or specific cases without the objective to generalize Aims at any variable which makes the desired difference Tries to say how things can be changed
A researcher moves an experiment out of the laboratory and into the real world. This type of research is called
a field study
which of the following is a general plan for implementing a research strategy?
a research design
Experimental research studies tend to have very________ internal validity but often have relatively ________ external validity.
a. High, low
How do studies sign the experimental research strategy differ from other types of research?
a. Only experiments can demonstrate a cause and effect relationship between variables
A Factorial study measures allergy symptoms before and after taking medication for a group taking the real medication and a control group taking a placebo. What kind of design is being used?
with-in subjects design
What are the aspects of an experiment?
An experiment is an investigation in which a hypothesis is scientifically tested. In an experiment, an independent variable (the cause) is manipulated and the dependent variable (the effect) is measured; any extraneous variables are controlled
What are the different types of research designs and strategies?
Descriptives ( case-study, naturalistic observation, survey) Correlational ( case-control study, observational study) non-experimental ( field experiment) Experimental (experiment with random assignment)(quasi-experiment) Review (literature review, systematic review)
What are the levels of validity for each research strategy?
Face validity-appears valid Content validity-topic of interest Construct validity-the degree to which a test measures what it claims, or purports, to be measuring Internal validity-refers to the degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables External validity- refers to the extent to which results from a study can be applied (generalized) to other situations, groups or events
How does holding a variable constant prevent the variable from becoming a confound?
It eliminates the possibility that the variable will be substantially different from one group to another.
Qualitative research ( categories of research)
It is non-numerical, descriptive, applies reasoning and uses words. Its aim is to get the meaning, feeling and describe the situation. Qualitative data cannot be graphed
Quantitative research ( categories of research)
It is numerical, non-descriptive, applies statistics or mathematics and uses numbers. It is an iterative process whereby evidence is evaluated. The results are often presented in tables and graphs.
which of the following is the primary goal for randomly assigning participants to treatment conditions in and experiment?
Minimize the likelihood that a participant variable (such as age or gender) becomes a confounding variable
Mixed research ( categories of research)
Mixed research- research that involves the mixing of quantitative and qualitative methods or paradigm characteristics. Nature of data is mixture of variables, words and images.
The students in one gym class receive a self-esteem program as part of their sports training to evaluate the program, a researcher measures self esteem for students before and after the program and compares their scores with those from another class that did not receive the program but was measured at the same two times. What kind of design is being used?
Repeated measure
Fundamental or basic research ( categories of research)
Seeks generalization Aims at basic processes Attempts to explain why things happen
a research study attempts to describe the relationship between self-esteem and birth order position by measuring self-esteem for each individual in a group of first-born boys, and then comparing the results with self-esteem for a group of later-born boys. Which research strategy is used?
a. non experimental
Cues given to participants about how they are expected to behave define which of the following terms?
b. demand characteristics
In order to establish an unambiguous relationship between two variables it is necessary to eliminate the possible influence of which of the following variables?
confounding variables
A study examining the relationship between humor and memory compares memory performance scores for one group presented with humorous sentences and a second group presented with non humorous sentences. The participants in one group are primarily 8 yr old students and those in the second group are primarily 10 year old students. In this study, age is potentially a(n)____________ variable.
d. confounding
