Threat to internal validity:
Researchers are implementing a health education program in public schools to create
awareness about teen pregnancy. During the process, one of the students becomes
pregnant, drops out of school, and commits suicide. At the end of the program,
researchers find a significant increase in students' awareness of teenage pregnancy. -
ANSWER-History- The suicide of a fellow student is likely to have a profound influence
on students' awareness.
Threat to internal validity:
A researcher decides to try a new mathematics curriculum in a nearby elementary
school and to compare student achievement in math with that of students in another
elementary school using the regular curriculum. The researcher is not aware, however,
that the students in the "new curriculum" school have computers to use in their
classrooms. - ANSWER-History- Computer usage in new curriculum schools
Threat to internal validity:
Researchers want to evaluate a pre-school readiness program for 3 to 4 year olds. To
determine the effectiveness of the program, the researchers randomly assign their
children either to participate in the readiness program or the daycare program. During
the course of the study several parents notice that their children are performing poorly in
the readiness program. These parents decide to take their children out of the program. -
ANSWER-Experimental Mortality (attrition)- the low scorers have dropped out. The loss
of low end scorers may artificially raise the overall mean for those in the readiness
program creating the impression of a program effect when there is none.
Threat to internal validity:
,Over a period of three years, a group of 20 teachers are observed closely by external
evaluators as they undergo a series of workshops aimed at improving their quality of
teaching. At the end, the evaluators observe the same 20 teachers, systematically, as
they teach. Their quality of teaching has improved according to criteria for improvement
(agreed-upon definitions and behavior). - ANSWER-Instrumentation- the observers may
have begun to drift away from their criteria.
*can argue maturation, regardless of the workshop, may have made improvements
anyway
Threat to internal validity:
Researchers were interested in examining the effectiveness of a cognitive-behavioral
treatment on students' stress levels. The researchers made contact with several
university counseling centers and recruited participants with extremely high stress
levels. Any post-treatment improvement could have been due to the treatment, but it
could also have been due to what? - ANSWER-Regression to the mean - it can occur
when participants have been selected on the basis of extreme scores, because extreme
(low and high) scores in a distribution tend to move closer to the mean (i.e., regress) in
repeated testing. It is possible the student might have gotten better without any
treatment. A control group would be helpful in reducing this th
Threat to internal validity:
Researchers are interested in examining how mindfulness influences motivation to
exercise. College students are randomly assigned either to the treatment condition
(e.g., weekly lectures plus journaling on mindfulness) or to the control condition (e.g., no
information or activities). Some students, who are assigned to the treatment condition,
begin feeling overwhelmed with the requirements of both school and the study. Many of
them stop going to the lectures and journaling, and evenly drop out of the study. At the
end of the study, researchers find those in the treatment condition had significantly
more motivation to exercise than those in the control conditio - ANSWER-Selection bias
- because random assignment was not used, the groups may not be equivalent at the
beginning of the study. That is, there may be differences between those who show up
first versus those who show up last.
Threat to internal validity:
A researcher uses the same set of problems to measure change over time in student
ability tosolve mathematics word problems. The first administration is given at the
beginning of a unit of instruction; the second administration is given at the end of the
unit of instruction, three weeks later. Improvement scores res - ANSWER-Maturation-
students get used to the same set of problems
Threat to internal validity:
Concerned about pretest sensitization, a researcher constructs a test that is extremely
difficult, and that is not content valid, and administers it to both the experimental and
control groups. The posttest used to measure gains in achievement is not as difficult,
and theexperimental group shows a slight larger improvement over the control group -
ANSWER-Instrumentation- varying levels of difficulty in the pre test and post test
Threat to internal validity:
Those students who score in the bottom 10% academically in a school in an
economically depressed area are selected for a special program of enrichment. The
, program includes special games, extra materials, special "snacks," specially colored
materials to use, and new books. The students score substantially higher on
achievement tests 6 months after the program is instituted. - ANSWER-Regression-poor
performing students used
*Argument for simple maturation is also viable-test scores improved with time and
practice
Threat to internal validity:
A researcher designs a study to investigate the effects of simulation games on
ethnocentrism. She plans to select two high schools to participate in an experiment.
Studentsin both schools will be given a pretest designed to measure their attitudes
toward minority groups. School A will then be given the simulation games during their
social studies classes over a three day period while school B sees travel films. Both
schools will then be given the same test to see if their attitude toward minority groups
has changed. the researcher conducts the study as planned, but a special, unplanned
documentary on racial prejudice is shown in school A between the pretest and the
posttest - ANSWER-History- the presence of unplanned documentary
Scenario: Renee (a 24 year old master's student) was studying attitudes toward women
using a questionnaire about affirmative action for women. She hypothesized that male
participants would express more support for affirmative action for women when they
expressed their attitudes toward a female experimenter, compared to a male
experimenter. Renee randomly assigned a group of male college students to have their
questionnaire administered by her or by her male advisor, a 50-year-old professor of
psychology. She conducted the study in two identical classrooms at the same time of
day. Renee found that the men tested in her own room reported more support for
affirmative action for women, compared to the men tested by her advisor. She
concluded that the gender of the examiner can make men express more liberal gender
attitude.
*What is the IV and DV?* - ANSWER-IV: gender of administrator
DV: attitudes toward affirmative action for women
Scenario: Renee (a 24 year old master's student) was studying attitudes toward women
using a questionnaire about affirmative action for women. She hypothesized that male
participants would express more support for affirmative action for women when they
expressed their attitudes toward a female experimenter, compared to a male
experimenter. Renee randomly assigned a group of male college students to have their
questionnaire administered by her or by her male advisor, a 50-year-old professor of
psychology. She conducted the study in two identical classrooms at the same time of
day. Renee found that the men tested in her own room reported more support for
affirmative action for women, compared to the men tested by her advisor. She
concluded that the gender of the examiner can make men express more liberal gender
attitude
*Identify the design (between- groups or within-groups? posttest only or
pretest/posttest?)* - ANSWER-between-groups, post-test only
The Seeing Red Experiment is considered to be what kind of simple experiment
design? - ANSWER-between- group, post-test only
Researchers are implementing a health education program in public schools to create
awareness about teen pregnancy. During the process, one of the students becomes
pregnant, drops out of school, and commits suicide. At the end of the program,
researchers find a significant increase in students' awareness of teenage pregnancy. -
ANSWER-History- The suicide of a fellow student is likely to have a profound influence
on students' awareness.
Threat to internal validity:
A researcher decides to try a new mathematics curriculum in a nearby elementary
school and to compare student achievement in math with that of students in another
elementary school using the regular curriculum. The researcher is not aware, however,
that the students in the "new curriculum" school have computers to use in their
classrooms. - ANSWER-History- Computer usage in new curriculum schools
Threat to internal validity:
Researchers want to evaluate a pre-school readiness program for 3 to 4 year olds. To
determine the effectiveness of the program, the researchers randomly assign their
children either to participate in the readiness program or the daycare program. During
the course of the study several parents notice that their children are performing poorly in
the readiness program. These parents decide to take their children out of the program. -
ANSWER-Experimental Mortality (attrition)- the low scorers have dropped out. The loss
of low end scorers may artificially raise the overall mean for those in the readiness
program creating the impression of a program effect when there is none.
Threat to internal validity:
,Over a period of three years, a group of 20 teachers are observed closely by external
evaluators as they undergo a series of workshops aimed at improving their quality of
teaching. At the end, the evaluators observe the same 20 teachers, systematically, as
they teach. Their quality of teaching has improved according to criteria for improvement
(agreed-upon definitions and behavior). - ANSWER-Instrumentation- the observers may
have begun to drift away from their criteria.
*can argue maturation, regardless of the workshop, may have made improvements
anyway
Threat to internal validity:
Researchers were interested in examining the effectiveness of a cognitive-behavioral
treatment on students' stress levels. The researchers made contact with several
university counseling centers and recruited participants with extremely high stress
levels. Any post-treatment improvement could have been due to the treatment, but it
could also have been due to what? - ANSWER-Regression to the mean - it can occur
when participants have been selected on the basis of extreme scores, because extreme
(low and high) scores in a distribution tend to move closer to the mean (i.e., regress) in
repeated testing. It is possible the student might have gotten better without any
treatment. A control group would be helpful in reducing this th
Threat to internal validity:
Researchers are interested in examining how mindfulness influences motivation to
exercise. College students are randomly assigned either to the treatment condition
(e.g., weekly lectures plus journaling on mindfulness) or to the control condition (e.g., no
information or activities). Some students, who are assigned to the treatment condition,
begin feeling overwhelmed with the requirements of both school and the study. Many of
them stop going to the lectures and journaling, and evenly drop out of the study. At the
end of the study, researchers find those in the treatment condition had significantly
more motivation to exercise than those in the control conditio - ANSWER-Selection bias
- because random assignment was not used, the groups may not be equivalent at the
beginning of the study. That is, there may be differences between those who show up
first versus those who show up last.
Threat to internal validity:
A researcher uses the same set of problems to measure change over time in student
ability tosolve mathematics word problems. The first administration is given at the
beginning of a unit of instruction; the second administration is given at the end of the
unit of instruction, three weeks later. Improvement scores res - ANSWER-Maturation-
students get used to the same set of problems
Threat to internal validity:
Concerned about pretest sensitization, a researcher constructs a test that is extremely
difficult, and that is not content valid, and administers it to both the experimental and
control groups. The posttest used to measure gains in achievement is not as difficult,
and theexperimental group shows a slight larger improvement over the control group -
ANSWER-Instrumentation- varying levels of difficulty in the pre test and post test
Threat to internal validity:
Those students who score in the bottom 10% academically in a school in an
economically depressed area are selected for a special program of enrichment. The
, program includes special games, extra materials, special "snacks," specially colored
materials to use, and new books. The students score substantially higher on
achievement tests 6 months after the program is instituted. - ANSWER-Regression-poor
performing students used
*Argument for simple maturation is also viable-test scores improved with time and
practice
Threat to internal validity:
A researcher designs a study to investigate the effects of simulation games on
ethnocentrism. She plans to select two high schools to participate in an experiment.
Studentsin both schools will be given a pretest designed to measure their attitudes
toward minority groups. School A will then be given the simulation games during their
social studies classes over a three day period while school B sees travel films. Both
schools will then be given the same test to see if their attitude toward minority groups
has changed. the researcher conducts the study as planned, but a special, unplanned
documentary on racial prejudice is shown in school A between the pretest and the
posttest - ANSWER-History- the presence of unplanned documentary
Scenario: Renee (a 24 year old master's student) was studying attitudes toward women
using a questionnaire about affirmative action for women. She hypothesized that male
participants would express more support for affirmative action for women when they
expressed their attitudes toward a female experimenter, compared to a male
experimenter. Renee randomly assigned a group of male college students to have their
questionnaire administered by her or by her male advisor, a 50-year-old professor of
psychology. She conducted the study in two identical classrooms at the same time of
day. Renee found that the men tested in her own room reported more support for
affirmative action for women, compared to the men tested by her advisor. She
concluded that the gender of the examiner can make men express more liberal gender
attitude.
*What is the IV and DV?* - ANSWER-IV: gender of administrator
DV: attitudes toward affirmative action for women
Scenario: Renee (a 24 year old master's student) was studying attitudes toward women
using a questionnaire about affirmative action for women. She hypothesized that male
participants would express more support for affirmative action for women when they
expressed their attitudes toward a female experimenter, compared to a male
experimenter. Renee randomly assigned a group of male college students to have their
questionnaire administered by her or by her male advisor, a 50-year-old professor of
psychology. She conducted the study in two identical classrooms at the same time of
day. Renee found that the men tested in her own room reported more support for
affirmative action for women, compared to the men tested by her advisor. She
concluded that the gender of the examiner can make men express more liberal gender
attitude
*Identify the design (between- groups or within-groups? posttest only or
pretest/posttest?)* - ANSWER-between-groups, post-test only
The Seeing Red Experiment is considered to be what kind of simple experiment
design? - ANSWER-between- group, post-test only
