Research methods

meta analysis

statistical procedure that allows them to combine findings from independently conducted studies -investigations that include estimates of age differences or age changes can then be compared using a single statistic -far superior approach

selective survival

study participants in a cross sectional design, are survivors of their respective age groups -thus they represent a healthier or luckier group of people than those in their cohort who did not live as long -perhaps they were more cautious, smarter, stronger

time of measurement

tell us the year or period in which a person is tested -social, historical, and cultural influences that are presently affecting people participating in developmental research

cohort

term used to describe the year (or period) of a persons birth

selective attrition

the fact that people who drop out of a longitudinal study are not necessarily representative of the sample that was originally tested -special case of nonrandom sampling

debriefing

the post-experimental explanation of a study, including its purpose and any deceptions, to its participants

scientific method

A logical, systematic approach to the solution of a scientific problem

age, cohort, and time of measurement

three factors that jointly influence the individuals performance on a given psychological measure at any point in life

ethical guidelines

-informed consent -debriefing -suggest resources -right to withdraw -confidentiality of data -opportunity to ask questions -overview of project

true experiment

The only research strategy that can determine that something causes something else; involves randomly assigning people to different treatments and then looking at the outcome.

anonymity

in addition to confidentiality, participants are guaranteed that their names will not be associated with their responses -condition if the study is a longitudinal one

validity

meaning that the test measures what it is supposed to measure -a test of intelligence should measure intelligence, not vision (tablespoon marked tspoon)

Institutional Review Board (IRB)

A committee at each institution where research is conducted to review every experiment for ethics and methodology.

correlation

A measure of the relationship between two variables through the this statistic -a positive correlation indicated the two variables are positively related -a negative correlation, indicates when one increases in value, other decreases

hypothesis

An educated guess as the relationship between events -type of relationship will depend on the variables correlation- 2 dependent variables (relationship only) true experiment- 1 randomly assigned iv and dv (cause and effect)

quasi-experimental design

An experiment that does not require random assignment to conditions. (comparing adults living in community with older adults in assisted living)

Informed Assent

Participant's agreement to participate in the absence of full understanding -commonly applies to individuals who have not attained legal majority and/or capacity (children, elderly)

reliability

a measure is reliable if it yields consistent results every time used (unreliable tablespoon in cooking) -use test-retest reliability, which is determined by giving the test on two occasions to assess whether respondents receive similar scores

random sampling

a method of poll selection that gives each person in a group the same chance of being selected -not usually possible to be random, so we settle for a group that is not systematically different from the desired population, may limit generalizations

cohort sequential design

a research design in which the longitudinal method is replicated with several cohorts -cohorts are compared at different ages -consist of two cohorts (1940 and 1930) compared at two ages (40 and 50)

most efficient design

a set of three design manipulating the variables of age, cohort, and time of measurement -it is most efficient because it enables the most amount of information to be condensed into the most inclusive data framework 3 designs: time sequential design cohort-sequential design cross sequential design

counfounds

a variable other than the level of the IV that is fairly consistently different between the groups

prospective study

a variant of the longitudinal design, in which researchers draw from a population of interest before the sample develops a particular type of illness or experiences a particular type of life event -ex: researchers who wish to study widowhood may recruit participants from a pop of married individuals, after time the now widows can be compared to the way they were prior

informed consent

an ethical principle that research participants be told enough to enable them to choose whether they wish to participate

random assignment

assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between those assigned to the different groups (computer generatede random numbers) -important bc it minimizes systematic differences btwn the groups that could result in confounds and taint the results -also a requirement for a true experiment

descriptive research design

essentially catalogs information about how people perform based on their age but does not attempt to rule out social or historical factors

independent variable

factor that researcher manipulates

time sequential design

method in which data are organized by age and time of measurement -researcher would compare scores of three or four age groups at three or four times of measurement (30 and 40 yr olds in the 2000s and 2010s)

dependent variable

outcome that researchers observe

laboratory studies

participants are tested in a systematic fashion using standardized procedures -most objective way of collecting data -limitations: inability to apply stimuli to real life experiences, findings may underestimate the individuals abilities in everyday life and not generalize to real world scenarios

longitudinal design

people are followed repeatedly from one test occasion to another -challenge of determining whether changes observed over time result from persons own aging or result of the changing environment -expensive and challenging -loses participants to death, relocation or lack of sustained interest

operational definition

refer to how the researcher has defined the variables for the purpose of the study -important for running and replication of the experiment

cohort effects

refer to the social, historical, and cultural influences that affect people during a particular period of time -influences present during early years of development that cause individuals to behave a certain way

cross sequential design

research design in which cohorts are examined at different times of measurement -comparing two or more cohorts (1940 and 1930) at two or more times of testing

correlational design

research method in which relationships are observed among variables as they exist in the world ex: high blood pressure and hostility were measured -variables were positively correlated, but correlation does not mean causation -may be a third variable that both are correlated with (smoking)

cross sectional design

researchers compare groups of people with different ages at one point in time -typically older adults are compared with younger adults -ensure age groups being compared have similar backgrounds (education) -different age groups may react differently to the test materials, causing performance differences -relatively quick and inexpensive, use latest tech

observational method

researches draw conclusion about behavior through careful and systematic examination in particular settings -participant observation: researcher participates in activities of the respondents (behavior of staff in nursing home) -may be used to determine whether an intervention is having its intended effects (method for aggression in alzheimers)

control variables

variables intentionally held constant between groups in order to help ensure that level of the IV is the only difference btwn the groups