Pysch Ch. 2

Standard Deviation

A measure of variability that indicates the average difference between the scores and their mean. Decides how not-average certain scores in a study are The standard deviation of the experiment is 79%, which is absolutely terrible. That's what Jane gets for skewing those monkey research results.

Random Presentation

A process by which chance alone determines the order in which a stimulus is given Choosing how/when to change or alter the independent variable randomly Rosa's used a coin to decide which hand to use in her experiment. That process is random presentation.

Survey

A quasi-experiment method in which questions are asked to subjects. When designing a survey, the researcher has to be careful that the questions are not skewed or biased towards a particular answer. Asking subjects questions about topics to find how a population responds or feels about something. A survey with a yes or no question is called a poll. Susie took a survey about how people generally liked the president, and 68% of people said they hated his guts.

Cohort-Sequential Study

A research method in which a cross section of the population is chosen and then each cohort is followed for a short period of time. A research method that includes the cross-sectional study, and also uses the concept of longitudinal study (but for a much shorter amount of time) Jane then went to the shelter to study the monkeys every Friday for 2 months. This is an example of a cohort-sequential study.

Naturalistic Observation

A research method in which subjects are observed in their natural environment. Studying subjects (usually animals or children) in their own habitat or environment Jane Goodall's experiment(s) concerning primates is a terrific example of naturalistic observation

Dependent Variable

The measured outcome of a study; the responses of the subjects in a study Whatever is measured in an experiment In Susie's experiment, she measured plant growth, thus the plant growth is the dependent variable.

Expectancy Bias

The researcher allowing his or her expectations to affect the outcome of a study. When an experimenter or researcher changes the results of an experiment because of their expectations of the outcome. Jane expected the monkeys to pray every Sunday, so she reported that they played less on the seventh day. This is an example of expectancy bias.

Personal Bias

The researcher allowing personal beliefs to affect the outcome of a study. When an experimenter or researcher changes the results of an experiment because of their beliefs or living style. Jane said that the monkeys selected the Bible over the Quran because God made all monkeys. This is an example of personal bias.

Random Sample

A sample group of subjects selected by chance Selecting participants of an experiment of research project purely by chance Jane's population was all of the monkeys at the animal shelter, and the monkeys were chosen via a random computer number generator. This is an example of random sample .

Representative Sample

A sample obtained in such a way that it reflects the distribution of important variables in the larger population in which the researchers are interested - variables such as age, income level, ethnicity, and geographic distribution. A group of people who represent the targeted population as a whole in every important aspect Jane only picked Roman Catholic monkeys, but left out all of the Buddhist monkeys in the animal shelter. Not all of the monkeys in the animal shelter were Roman Catholic, thus this is an example of a NON-representative sample.

Hypothesis

A statement predicting the outcome of a scientific study; a statement describing the relationship among variables in a study An educated speculation about how an experiment will turn out Susie's hypothesis was that her plants would grow more in blue light than red light, but she had to perform her experiment first in order to find the truth.

Independent Variable

A stimulus condition so named because the experimenter changes it independently of all the other carefully controlled conditions Whatever is purposely changed or altered during the experiment by the experimenter In Susie's experiment the color of light was changed, so that was the Independent Variable (IV).

Cross-Sectional Study

A study in which the representative cross section of the population is tested or surveyed at one specific time A research method where one group of people (or a representative sample of that group) are researched or experimented at one specific time. Jane watched the monkeys immediate behavior after giving them morphine. This is an example of a cross-sectional study.

Theory

A testable explanation for a set of facts or observations. In science, a theory is not just a speculation or a guess. An idea that explains a phenomenon or certain observations based on evidence and supported by data. For example, the theory of evolution or the theory of a multi-universe.

Correlative Study

A type of research that is mainly statistical in nature. Correlative studies determine the relationship between two variables. A type of research that determines 1) how two things are related and 2) how strong that relationship is, but cannot determine if one thing was caused by another Determining if SAT scores is related to GPA would require a correlative study but one could not determine if higher GPA scores CAUSE higher SAT scores that way.

Longitudinal Study

A type of study in which one group of subjects is followed and observed for an extended period of time. Observing how a subject behaves for a long period of time That man has been following my whole life...he must be performing a longitudinal study!

Double-Blind Study

An experimental procedure in which both researchers and participants are uninformed about the nature of the independent variable being administered. No one in the study knows which group of participants have which independent variable, except for a third party Neither Jane nor the monkeys knew which group of primates had been given holy water. This is an example of a double-blind study.

Random Assignment

Each subject of the sample has an equal likelihood of being chosen for the experimental group or the control group Whether or not each person is put into the control group or the treatment group is decided purely by chance Putting the subjects in an alphabetical list and picking every other one to receive treatment is an example of random assignment.

Ex Post Facto

Research in which we choose subjects based on a pre-existing condition Doing an experiment on people with a condition that they have or have had, or on people who have gone through an experience. An experiment on people who have gone through a hurricane, or have survived Leukemia is an ex post facto experiment.

Operational Definitions

Specific descriptions of concepts involving the conditions of a scientific study. Operational definitions are stated in terms of how the concepts are being measured, and what operations are being employed to produce them. The definition of how something is measured in a scientific study. Love cannot be measured, but the amount of Oxytocin the brain produces can be measured.