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Variables
Notes
Question | Answer |
---|---|
Independent Variable | Variable that is manipulated or has pre existing groups. |
Dependent Variable | Measurable response or outcome. |
Extraneous Variable | that is not accounted for, any outside force that is changing the DV |
Confounding Variable | Systematically varies with IV |
Controlled Variable | The part of an experiment that is measured before the experiment is conducted then studdied and measured after the experiment is conducted inorder to form a conclusion. |
Conclusions of Relationships | In a simple relationship conclusion there is no implication that any one variable (IV) is the single, independent cause for subsequent results. |
Conclusions of Causality | In a cause-effect conclusion there is very strong language used to directly state that some induced change in an independent variable (called a manipulation) will cause or produce a specific kind of change or result in the dependent variable. |
Random Selection | is a subset of individuals (a sample) chosen from a larger set (a population). Each individual is chosen randomly and entirely by chance |
Random Assignment | is an experimental technique for assigning subjects to different treatments or no treatment |
Experimental Group | Experimental Group is the one that receives the unusual or innovative condition or treatment. |
Control Group | The Control Group is a group to compare with the Experimental Group. Control Groups may receive no treatment at all (called a “do nothing” Control Group), or sometimes may receive some previously used treatment (an example follows later). |
Manipulation | |
True Experiment | Those that do randomly assign |
Quasi-Experiment | experiments that do not randomly assign for one reason or another |
Placebo | a non-active treatment. It looks like and tastes like the real thing, but has no active ingredient. |
Single Blind Experimen | it is important to control participants’ expectations about outcomes by keeping them unaware of what treatment condition they receive. This is called a blind experiment |
Double Blind Experiment | Doctors and pantients are unaware of experiment |
Internal Validity | Internal validity is the confidence one has that outcomes on the dependent variable are a direct result of the manipulation of the independent variable, and not due to extraneous variables. |
Posttest-Only Control Group Design | is a measure of the dependent variable coming after the manipulation. |
Pretest Posttest Control Group Design | a measure of groups on the dependent variable or some important extraneous variable that comes before the manipulation. |
Matching | Matching is used to create and guarantee equivalence between groups on an important extraneous variable. Matching simply is the researcher only includes participants in one group for an approximate matching participant’s score in the other group. |
Comparing Homogeneous Groups | |
Negative Correlation | a negative (indirect or inverse) correlation, correlation is a trend in which people who have relatively higher scores on one of the two variables are more likely to have lower scores on the other variable. |
Positive Correlation | a positive (direct) correlation, is a trend in which people who have relatively higher scores on one of the two variables are more likely to have higher scores on the other variable as well. |
No Correlation | Straight line, is the conclusion when there is no consistent pattern in the relationship between the pairs of scores. |
Scatterplot | A scatter plot describes the direction (positive or negative) and degree of correlation. |
Interpreting Data in a Correlation | correlation is a number 0-1.00 is positive or negative.closer it is to the number 1, the more consistent the relationship is between the variables. The closer the calculated result is to 0, the more inconsistent the correlation between variables is. |
Relationship Studies | - Make decisions about people/things- Make selections |
Prediction Studies | - Make decisions about people/things- Make selections |
Predictor Variable | - Similar to IV in experiments - Used to make prediction |
Criterion Variable | - Similar to DV in experiments |
External Validity | is the confidence one has that the results of the experiment are applicable outside the experimental setting. Will the manipulation work with participants who were not in the experiment or who are not in the experimental setting? |
R | stands for random assignment (or randomization) in the placement of participants to different treatment groups. Experiments that use R are called True Experiments. |
X | stands for manipulation of the Independent Variable. |
O | stands for observation on the Dependent Variable. |
Descriptive research | does not attempt to manipulate or change situations. Descriptive research simply reports relationships between variables, situations or conditions as they are. |
Cross-sectional developmental research | research involves selection of people currently different from each other on the independent variable. |
comparative research design | Comparing for research |
longitudinal research | one original group |
observational | conclusions are reached on the basis of observation (looking) rather than asking people to self-report or tell us about themselves. |
Self-Report research | involves any methodology that asks participants to provide information about themselves. These methodologies include mailed questionnaires |
Reliability | reliability refers to how consistently instruments measure. If an intelligence test suggested a different result for the same client each time the test was administered |
Test-retest reliability | determines an instrument’s ability to produce consistent or stable results over time. |
Validity | the judgments about confidence that a instrument measures what is intended. Does an instrument produce results that are appropriate for the stuff of those being measured and are interpretations of the results appropriate for what was intended? |
Content validity | is a judgment that an instrument should be appropriate for measuring what was intended for the audience being measured. |
pilot test | is a critique by knowledgeable persons about whether the content is relevant |
concurrent validity | If the established criterion is measured at about the same time as the new test is administered |
predictive validity | If the criterion is measured at some date in the future |
generalizable | The purpose of sampling is to be efficient and economical while at the same time enabling conclusions based on the sample to be applicable, or generalizable, to the population from which they were selected. |
random sampling | trusted to produce samples representative of population characteristics within predictable margins of error or misrepresentation. |
stratified sampling method | the researcher is conscious of some known population characteristics that they wish to represent. |
proportional stratified | the researcher can guarantee that known population characteristics are represented in the sample in the same proportion as they exist in the population. |
Systematic sampling | The process is to divide the desired sample size into the known population size to create a result called “k”. The researcher then systematically selects every “kth” person from the list. |
Cluster sampling | selects members from a population in groups rather than individually or one at a time. The random |
convenience sampling | When you select participants based upon their availability |
Sampling bias | is a failure on the part of the researcher to give every member of a population the same fair chance for selection. If some members of a population do not have an opportunity to be selected |
Sampling error | is a source of possible misrepresentation that exists in any sample. Any time a sample is taken and all members of a population are not used |
Strength of relationship | o R=0.0 to 0.3 -> weak relationshipo R=0.3 to 0.7 -> moderate relationshipo R=0.7 to 1.0 -> strong relationship |
Problems with Correlational Studies | - Correlation = no causation- Third variable problems- Problem of directionality |
A note about Correlations | - Correlation = no causation |
Causal-Comparative | - No cause and effect |
Experimental | - Cause and effect relationship |
Pearson’s r | - Determines strength of relationship- Determines Direction of relationship |
Psychology Definition | is an academic and applied discipline involving the scientific study of mental functions and behavior. Psychologists study such phenomena as perception, cognition, emotion, personality, behavior, and interpersonal relationships. |