research methods final exam

the results of a successful ABAB design...

with a treatment designed to increase the frequency of a desired behavior would look like the graph below: (graph of ABAB reversal design)

it is longitudinal in that

within each cohort there will be a series of measurements over a long period of time and within-subject comparisons will be made.

longitudinal study

you follow things over a long period of time same subjects over a long period of. time. can last from 12 days to decades

teacher and student both have expectations for a high grade

you get high grades students high expectation can offset some of the teachers low expectation

posttest only non equivalent control group design

used to show that a treatment was effective in a preexisting treatment group.

teacher expectations impact trade ___ than students expectations

way more

this is better than a post-test only design because

we can factor in the level of the dependent variable before and after the manipulaltion is introduced and icrease our confidence that observed changes are due to the manipulation.

in a well executed experiment....

we can say there is LIKELY a cause and effect relationship between the independent and dependent variables

with natural experiments,

when there are tornado sirens, we cant control the tornados, but we can collect data on it. we can see how many people took shelter. how many times does it take for the boy to cry wolf to make people want to not take shelter?

statistics

when you have 2 groups, your options are simple. you have an independent t test or a dependent t test independent - 2 diff groups of people dependent - same group test them twice 2 groups, look at data, look at average and standard deviations, if data is really unusual, that is a surprise and statistics will help you see this

ABA design

where A means baseline/no treatment and B means treatment is applied A(baseline) ---> B(treatment) ---> A(reversal)

it is common for researchers to study behavior change with age.

For example, developmental psychologists and health psychologists and those studying personality and psychopathology want to know how behaviors during childhood affect individuals throughout the lifespan, or if behaviors and traits observed in childhood are stable or change over the course of an individuals' life, or if events affect people of different ages differently.

replications: the best way to strengthen the external validity is to...

replicate the ABA design with multiple participants

replications: the major limitation of single case desidns is that

since they are limited to a single participant it is difficult to generalize findings

one group is measured after receiving the....

"treatment" and another control group who did not receive the treatment is measured at the same time

quasi means

'resembling' or 'having some of the features of' - so a quasi-experiment resembles and experiment; it has some but not all of the features of an experiment.

quasi experimental design 3 types

1 group (pre/post test) post test only (non equivalent) pre/post test (non equivalent)

a baseline requires at least ___ data points, so the investigator can make sure the behavior is stable and not increading or decreasing

3

longitudinal developmental research design

A longitudinal design is a one-group within-subjects nonexperimental design or a quasi-experimental time series design.

in an _______ design

ABAB, treatment is reintroduced in a fourth phase

how do you know if it is an experiment or not?

In an experiment: The independent variable is manipulated, and the dependent variable is measured All other variables are controlled

cross-sectional longitudinal designs

In practice there are many deisgns that are not purely longitudinal or cross-sectional. Designs that have features of both cross-sectional and longitudinal designs are mixed developmental designs. For example, a researcher is following groups people who were 10, 20 and 40 and lived in or near New Orleans at the time of Hurricane Katrina. She is studying the impact of the hurricane on their physical and mental health and careers and schooling. She has them answer a set of questions every year and will follow-up for at least 10 years.

one group pretest-posttest design

In this nonexperimental design participants complete some relevant of interest and then the quasi-independet variable is manipualted and then they complete a posttest...and there is no control or comparison group.

important distinction

Quasi-experimental studies include some attempt to limit or control threats to internal validity, but do not have the full control of an experiment.

quasi-experimental designs fall short of this standard

Sometimes the independent variable is measured but not manipulated by the researcher, for example if we want to study stress levels in people who were exposed to a tornado compared to people who were not, the researcher doesn't control the tornado. Sometimes the independent variable is characteristic like gender, or ethnicity, or education, that can't be manipulated.

replications

The major limitation of single case designs is that since they are limited to a single participant it is difficult to generalize the findings.

of course there are also disadvantages to longitudinal studies

Time - it takes years or decades to complete longitudinal studies Money - it is very expensive to track people over time Attrition/Mortality - participants lose interest, can't be located, or die during the course of the study

all research occurs over time.....

We examine the impact of an intervention over weeks, months, and even years...This does not mean that all research is developmental. It becomes developmental when the amount of time is significant or age is the dependent variable, such as in comparing people of different ages, or examining how the same person reacts to an intervention or answers questions at one age versus at another age.

in a quasi-experiment we can say that there COULD be.....

a cause and effect relationship between the variables, but with much less certainty than in an experiment

baseline period

a baseline period is a control perios to measure the frequency, intensity, or duration of some behavior before a manipulaton is made. for instance, to see how many times a dog barks at a stranger before a shock collar is introduced, or how often it jumps on a person before positive reinforcement is introduced, or how many times a chil with ADHS gets out of his sear before behavioral treatment or medication is introduced

In quasi-experimental longitudinal designs

a change in the independent variable is measured BEFORE AND AFTER some event, such as a divorce, a parent's divorce, graduation, a natural disaster such as a major hurricane or earthquake.

the major strength of cross-sectional designs is that

a researcher doesn't have to wait for people to age in order to make predictions about behavior as people age -- they can merely study groups of people of different ages.

this type of design is also call an ______-

aba design, where A means baseline/no treatment and B means treatment is applied A (baseline) --> B (treatment) --> A (reversal)

global warming

causes more extreme highs and lows - very long term phenomenon

how can we make the schitzo study better?

add a control group if we have a control group, we not have a PRE/POST TEST CONTROL GROUP of people who dont have schitzo at all or peope with schitzo who get a placebo called non equivalent groups because the groups are not the same

complex experimental designs

add more than 2 groups add more than 2 variables a lot of other variables to look at (car example)

by showing that the baseline behavior only changes....

after the treatment is introduced there is greater confidence that the change is due to treatment rather than to some other factor

they might begin measuring a baseline for....

all the children on day one, and then introduce the treatment to J on day 4, to K on day 6, and to M on day 8.

what happens when you randomly assign people to groups or randomly select subjects

all the subject variables that do exist end up cancelling eachother out. if you cant do random selection, you can do random assignment. cant do this with quasi

the cohort effect

also called a generation effect - occurs when differences between two or more different age groups are due to differences other than their age. That is, each cohort has had unique experiences that other cohorts haven't. For example, today we find that far fewer very elderly persons use computers as do younger groups of people. However there is nothing about being old per se that makes one less likely to use a computer. It is most likely a corhort effect, where older adults did not grow up using computers. In the future, when you are 'old' you will probably use computers because you've been using them most or all of your life. Differences in computer use are correlated with and not caused by age. The difference in use by age is due to familiarity with computers.

reversal design is also called

an ABA design

natural experiments

an empirical study in which individuals (or clusters of individuals) are exposed to the experimental and control conditions that are determined by nature or by other factors outside the control of the investigators.

in a multiple baseline across participants design,

an investigator would have a few participants and introduce the treatment on a different day for each. For example, suppose they have three children J, K, and M, with ADHD and they are providing a treatment to decrease the number of times the child gets out of their seat

in clinical studies if there is a placebo (control group),

and the meds seem to be working for the experimental group, you have to give the drug to the placebo group

In fact, some are finding that young adults such as the average college age student

are behaving like those reared during the depression...and some believe that coming of age during "the great recession" is the reason for their attitudes towards money....so it may be that life experience rather than age accounts for frugality...

developmental research designs

are nonexperimental designs What makes them different from the other designs discussed is that they are used to study changes in behavior that are related to age/the passage of time.

experimental and quasi-experimental research designs

are similar in that both strategies investigate relationships between variables by comparing groups of scores. There are also important differences between them.

a baseline requires

at least three data points, so the investigator can make sure the behavior is stable and not increasing or decreasing

with some treatments,

behavior does not return to baseline-- if you learn something is may not be possibe to unlearn it

with some treatments....

behavior does not return to baseline---if you learn something it may not be possible to unlearn it! in such cases the investigator might use a multiple baseline design to show that the treatment had an effect

cross-sectional study

bring abunch of different ages together to test them saves you a lot of time

the single case designs are thus a ___ as well as a _______

clinical tool research tool

the single case designs are thus a

clinical tool as well as research tool

cross-sectional designs .....

compare people of different ages at the same time, longitudinal studies follow a group of people for a long period of time - sometimes decades. And there are also combined designs that are both cross-sectional AND longitudinal at the same time.An example of a combined design is presented at the end of this section.

natural experiments are employed as study designs when

controlled experimentation is extremely difficult to implement or unethical, such as in several research areas addressed by epidemiology (like evaluating the health impact of varying degrees of exposure to ionizing radiation in people living hear Hiroshima at the time of the atomic blast) and economics (like estimating the economic return on amount of schooling in US adults)

People born at different times

have had different experiences due to events that occurred during their respective life times.

so, ij Js behavior changes after day four and Ks and Ms remains the same until they receive treatment,

hen there is greater confidence that the change in J's behavior is due to treatment rather than to some event that occurred on day 4, say a substitute teacher, a change in weather, a different school activity.

however, as your textbook points out, there are several threats to internal including

history maturation testing instrument decay regression toward the mean look in txtbook to get definitions for these terms (pg 224-226)

for example...

if a researcher wanted to see if a treatment for anxiety was effective in a group of people who were treated, then she might compare them to a group of people with anxiety who were not treated, and see which group scores higher on a measure of anxiety,

what are single case experimental designs used to determine

if a treatment or other manipulation has an effect on the participant

problems with cross sectional

if you bring in a 10 year old and an 80 year old, their life experiences are very different - its hard to know the reason for the differences you find if you are abused, you are more likely to die

multiple baseline designs

in a multiple baseline across participants desgin, an investigator would have a few participants and introduce the treatment on a different day for each. for ex, suppose they have 3 kids J, K, and M, with ADHD and they are providing a treatment to decrease the number of times the child gets out of their seat. they might begin measuring a baseline for all of the kids on day one, then introduce the treatment to J on day 4, to K on day 6, and to M on day 8 so, if Js behavior changes after four and K and Ms remains the same until they receive treatment, then there is greater confidence that the change in Js behavior is due to treatment rather than to some event that occured on day 4, say a substitute teacher, a change in weather, a different school activity

reversal design

in this design, the investigator observes measures the behavior of the individual over a baseline period

For other examples

in this election season, consider how pollsters look at age in their surveys to predict what people of different ages will do. They contrast which party people of different ages are likely to vote for, what issues are most important to voters of various ages, and how likely people of different ages are to go to the polls and vote.

In helena montana, a smoking ban was in effect in all public spaces

including bars and restaurants, during the six-month period from June 2002 to December 2002. Helena is geographically isolated and served by only one hospital. The investigators observed that the rate of heart attacks dropped by 40% while the smoking ban was in effect. Opponents of the law prevailed in getting the enforcement of the law suspended after six months, after which the rate of heart attacks went back up. This study was an example of a natural experiment, called a case-crossover experiment, where the exposure is removed for a time and then returned. The study also noted its own weaknesses which potentially suggest that the inability to control variables in natural experiments can impede investigators from drawing firm conclusions.

replications: each successful replication......

increases confidence that observed changes are due to the intervention/manipulation rather than to a feature of the participant (external validity), or the investigator or the setting (internal validity)

each successful replication....

increases confidence that observed changes are due to the intervention/manipulation rather than to a feature of the participant (external validity), or the investigator or the setting (internal validity).

baseline period

is a control period to measure the frequency, intensity, or duration of some behavior before a manipulation is made. For instance, to see how many times a dog barks at a stranger before a shock collar is introduced, or how often it jumps on a person before positive reinforcement is introduced, or how many times a chil with ADHD gets out of his seat before behavioral treatment or medication is introduced.

cohort

is a group of individuals who were born at about the same time and grew up under similar circumstances.

other varibles to look at

main effect variable interaction = vatiables sleeper effect if you wanna test something, you have to come up with a way to meaasure and test it - an operational definition

as scientists, goal is to.....

make sure you have enough evidence to support what your saying, and you have to find a way to examine your evidence to see if it is significant

the experimental strategy creates the groups by

manipulating an independent variable

cross-sectional developmental research design

is a nonequivalent groups, between-subjects design where each group is composed of individuals of different ages. For example, one group might be all 20 year old individuals and a comparison group might be 50 year old individuals. Researchers might want to see if there are differences in stress or well-being or life satisfaction or worry about the future or health concern at different ages. You read or hear about cross-sectional research all the time. For instance, recent studies show that younger Americans are more likely than older Americans to be unemployed, have faster reaction times, support gay marriage, be vegetarian, watch reality TV shows, take psychotropic medications and are less likely than older adults to be divorced, vote in an election, have serious health problems, read books, feel that they will be well-prepared financially for retirement.

pretest-posttest nonequivalent control group design

is a quasi-experimental design. It goes further than the posttest only design with respect to controlling variables.

natural experiment

is an empirical study in which individuals (or clusters of individuals) are exposed to the experimental and control conditions that are determined by nature or by other factors outside the control of the investigators. The process governing the exposures arguably resembles random assignment. Thus, natural experiments are observational studies and are not controlled in the traditional sense of a randomized experiment (an intervention study). Natural experiments are most useful when there has been a clearly defined exposure involving a well defined subpopulation (and the absence of exposure in a similar subpopulation) such that changes in outcomes may be plausibly attributed to the exposure.[1][2] In this sense, the difference between a natural experiment and a non-experimental observational study is that the former includes a comparison of conditions that pave the way for causal inference, but the latter does not.

rate of behavior in reversal design...

is low during the baseline phase, increases when treatment is introduced, returns to baseline when treatment is withdrawn increases again when treatment is reintroduced

post test only (non equivalent)

is this medication working? you can instead bring in normal people and run abunch of tests on their thoughts and behaviors and compare them to the schitzo people. all you have is after the pill! no pretesting! the schitzo people on medicine and the "normal" people should have the same behavior if the meds are working

the best way to strengthen the external validity

is to replicate the ABA design with multiple participants

jackson heart study

longest running research program in the country - are looking at the incidence of heart disease - black men have a much higher incidence and chance of dying from heart attacks than white men - stress due to money

what if you wanna collect data over a long period of time?

longitudinal study

there is a threat of assignment bias

maybe people who got treatment for anxiety are more motivated to get better, or the school with a new freshman orientation is better managed, or the community with new traffic regulations is more attentive to resident safety...

in such cases the investigator might use..

multiple baseline design to show that the treatment had an effect

the quasi-experimental strategy define the groups with a....

nonmanipulated variable such those who experienced some event and those who did not (e.g., combat veterans Vs noncombat veterans, crime victims Vs people who are not victims, etc.).

natural experiments thus, natural experiments are ____ and are not controlled in the traditional sense of a randomized experiment (an intervention study)

observational studies

for example, imagine that two schools are being compared....

one city or school may have budget cuts, or experience an event such a school shooting or tornado or other event that the other does not, so history effects remain a threat to internal validity. Or if a treatment group is compared to a no-treatment group a treatment group may have more motivation to recover/get better than a non-equivalent group that did not receive treatment, so it would be difficult to know if improvements were observed because of the quality of the treatment or because of the higher motivation of the treatment group.

In nonexperimental longitudinal designs

one group of individuals is measured over time and the independent variable is age. For example, how does a score on some measure change with age?

in a multiple baseline across settings design the investigator might want to work with....

one participant, and establishes a baseline across a number of settings. Continuing the example of out of seat behavior in a child with ADHD, in a multiple baseline across settings design the researcher might measure the frequency of the behavior in several settings and establish a baseline for school, home, and church and then might conclude that if the behavior changes across all three setting then the change is due to the effect of treatment rather than to some change at school or in the home o rat church.

in a multiple baseline across settings design the investigator might work with _____ participant, and establishes a baseline across a ______ of settings. continuing the example of out of seat behavior in a child with ADHD, in a multiple baseline across settings design the researcher might measure the frequency of the behavior in several settings and establish a baseline for school, home, and church and then might conclude that if the behavior changes across all three settings then the changes due to the effect of treatment rather than to some change at school or in the home or at church

one, number

longitudinal studies are done....

only when following people for a long time is the only way to get the answers

the major weakness is that...

participants may differ in more ways than age alone. For example, if we find that 85 year old persons are more frugal with their money than 55 year olds, this may not merely be a difference that has to do with age. It may well be because the older person was born during the great depression and a child during World War II when many people had financial difficulties, while the 55 year old was a child during the more affluent post-war expansion.

in a true experiment

participants would be randomly assigned to a treatment or control condition

if medicine is not workng and is having some bad side effects

people who are taking the meds have the right to decide whether they wanna take it or not. drug manufacturers dont make drugs they cant make money off of, worried about lawsuits. (if the manufacturer sees that the drugs arent working, they have the right to withdrawal if from patients)

schitzo quasi experimental design with taking meds

people who have schitzo (not a random group) people who have schitzo, your testing this drug, all you can do is record behavior before and after drug (did anything change?) it is now quasi because you cant randomly select these people, they are schitzo people

natural experiments the process governing the exposurs arguably resemble

random assignment

the ______ is low during the baseline phase, increases when treatment is introduce, returns to baseline when treatment is withdrawn, and increases again when treatment is reintroduced

rate of behavior

quasi experimental research designs

research designs in which the independent variable involves a grouping but in which equivalence has not been created between the groups still good experimental research designs, you tend to have to get more participants to have a convincing argument that its really working

finally, in the _______ the treatment is withdrawn, and the behavior observed one more time to make sure changes in it are due to the treatment and not to some other factor. without the reversal phase it is not a true experiment

reversal phase

finally, in the _____ phase....

reversal phase when the treatment is withdrawn, and the behavior observed one more time to make sure changes in it are due to the treatment and not to some other factor without the reversal phase it is not a true experiment

many behavior therapists and behavior analusts use single case designs to..

see if their treatment is effective with a given client, for instance, if they are working with a shy client theu might measure minutes of eye contact during an hour each day, or number of times initiating conversation in the classroom. before and afte treatment begins. if there is no change, then this is a sign for the therapist to change what they are doing and try a different intervention

organizational psychologists might use a single case design to

see the impact of their interventions on a business or other organization. for instance, they might look at absenteeism before and after a program to boost attendance, or new grants or patents submitted before and after a program to boost creativity or productivity

1 group only (quasi)

seeing behaviors before and after the medicine. quasi because its not a random group

experiments are designed to...

show cause and effect relationships between variables

there is no _____ assignment, but....

since the groups are measured before and after treatment there can be greater confidence in the similarity of the groups and thus that the treatment alone is responsible for any differences observed posttreatment.

However, this improvement does not completely solve the problem of assignment bias,

since the participants are not randomly assigned to groups. The pretest can show that the groups are similar with respect to the dependent variable, but not that they are similar with respect to other variables. For instance, there could be history effects where one group has different experiences than the other in between the pre and posttests.

single case experimental design

single case experimental designs differ from case studies in that they are not merely observational, they are true experiments these designs are used to determine if a treatment or other manipulation had an effect on the participant the researcher might study one individual or one "case" if the case is a single entity such as a single classroom, school, park, or business

helena montana example

smoking ban was in effect here in all public spaces, including bars, restaurants, during the 6 month period from june 2002 to december 2002. Helena is geographically isolated and served by only one hospital. The investigators observed that the rate of heart attacks dropped by 40 percent while the smoking ban was in effect. Opponents of the law prevailed in getting the enforcement of the law suspended after 6 months, after which the rate of heart attacks went back up. this study was an example of a natural experiment, called case-crossover experiment, where the exposure is removed for a time and then returned. the study also noted its own weaknesses which potentially suggest that the inability to control variables in natural experiments can impede investigators from drawing conclusions

rather than being analyzed ____ reversal designs are usually analyzed graphically

statistically

rather than being analyzed ________......

statistically, reversal designs are usually analyzed graphically

what if teacher has high expectations, studrent has low expectations

student gets good grade

natural experiments are employed as

study designs when controlled experimentation is extremely difficult to implement or unethical, such as in several research areas addressed by epidemiology (like evaluating the health impact of varying degrees of exposure to ionizing radiation in people living near Hiroshima at the time of the atomic blast) and economics (like estimating the economic return on amount of schooling in US adults)

why cant you do a random selection with quasi-experimental designs?

subjects have to be chosen because of who they are, not randomly

the advantage of pretest-posttest nonequivalent control group design is

that if the treatment and control groups have similar scores on the pretest and different scores on the posttest, then they can be more confident that changes in the scores are due to the treatment and not to time related factors or to pretest differences on the dependent variable

the difference between a natural experiment and a non experimental observational study is

that the former includes a comparison of conditions that pave the way for causal inference, but the latter does not

Another advantage is

that the researcher can observe how a single individual changes over 10 years rather than making inferences by comparing 20 year olds to 30 year olds at the same time, as she would in a cross-sectional design.

the threat of assignment bias means....

that we cannot be sure that group differences are caused by the treatment, so the design is considered nonexperimental.This type of experiment is useful when random assignment is not possible or is not practical.

why are quasi experimental designs hard to do

thaws mom was struck by lightning, she will hide when there are tornado warnings. not just that a couple false alarms will make people avoid shelter when they should, it instead means we cant control thism but in general people will stop paying attention (CANT CONTROL SUBJECT VARIABLES)

The advantage of a longitudinal design is

the absence of cohort effects. If we follow a group of 20 year olds and measure them again at age, 30 all of them are part of the same cohort of individuals.

this type of research is often done to look at...

the effect of new treatments. And keep in mind that the word 'treatment' must be used loosely. Treatment might mean what we usually think of as in a new medication or therapy. And 'treatment' might mean changing the speed limit or adding lights to a road and comparing the number of accidents in a road with a different speed limit or lighting conditions over the same period of time, or looking at how a new Freshman orientation affects grades compared to a group of freshman who receive no such orientation, or how receiving access to the internet affects knowledge of current events compared to a group of people who do not have internet access.

in a reversal design....

the investigator observes and measures the behavior of the individual over a BASELINE period

if the independent variable is manipulated by the experimenter....

the research is not experimental if other variables aren't controlled. For example, if a researcher is testing a treatment in a treatment group and a no-treatment control group, if there is not random assignment to the groups it is not a true experiment.

Pollsters don't only look at age. They also contrast

the sexes, people of different incomes, ethnicities, education levels, etc. All of these variables are non-experimental, since we can't randomly assign people to an age, sex, education elvel or ethnicity...and only age is developmental

the study is cross-sectional in that...

there are three cohorts and between-subjects comparisons will be made

natural experiments are most useful when

there has been a clearly defined exposure involving a well defined subpopulation (and the absence of exposure in a similar population) such that changes in outcomes may be plausibly attributed to the exposure

in a posttest only nonequivalent control group design

there is no random assignment so the groups are nonequivalent

in Louisiana

they are doing the longest longitudinal study ever - testing to see if people in the south have a higher probability of getting cancer

for example

they complete a measure of depression, then participate in therapy or take an antidepressant medication,a nd complete the measure of depression again they rate their anger and then play a violent video game and rate their anger a second time they evaluate a product then watch an ad for it and evaluate the product again

single case experimental designs

they differ from case studies in that they are not merely observational, they are TRUE EXPERIMENTS

single case experimental design number of cases to study

they might study one individual if the case is a single entity such as a single classroom, school, park, or business

those in preexisting treatment group are compared....

to a control group of similar types of persons

why do behavior therapists and behavior analysts use single case designs

to see if their treatment is effective with a given client, for instance, if they are working with a shy client they might measure 'minutes of eye contact' during an hour each day, or number of times initiaing a conversation in the classroom, before and after treatment begins. If there is no change, then this is a sign for the therapist to change what they are doing and try a different intervention.

why might organizational psychologists use a single case design

to see the impact of their interventions on a business or other organization. For instance, they might look at absenteeism before and after a program to boost attendance, or new grants or patents submitted before and after a prgraom to boost creativity or productivity.

then a ____ phase begins. the ____ is introced and the behavior is observed and measured again

treatment

then a ____ phase begins

treatment the treatment is introduced, and the behavior is observed and MEASURED again

In ABAB design,

treatment is reintroduced in a 4th phase