Research Methods

Applied Research

-Research that psychologists conduct to solve practical problems -Research that has clear, practical applications -The other category of research is basic research, which explores questions that are of interest to psychologists but are not intended to have immediate, real-world applications

Scatter Plot

-A graph of correlated data -Graphs pairs of values, one on the y axis and one on the x axis -The closer the points come to falling on a straight line, the stronger the correlation

Random Assignment

-A method of assigning participants to conditions such that each participant has an equal chance of being placed into experimental groups -Assignment is the process by which participants are put into either an experimental or a control group -It limits the effects of confounding variables based on differences between people -Using random assignment diminishes the chance that participants in the two groups differ in any meaningful way

Random Selection

-A method of selecting a sample from a population -Every member of the population has an equal chance of being selected. Random selection increases the likelihood that the sample represents the population and that one can generalize the findings to the larger population

Stratified Sampling

-A process that allows a researcher to ensure that the sample represents the population on some criteria

Case Study

-A research method used to get a full, detailed picture of one participant or a small group of participants -Allows researchers to get the richest possible picture of what they are studying, but the focus on a single individual or small group means that the findings cannot be generalized to a larger population

Hypothesis

-A statement that expresses a relationship between two variables -in an experimental hypothesis, the DV depends on the IV (a change in the IV will produce a change in the DV) -In testing a hypothesis, researchers manipulate the IV and measure the DV

Correlation

-A statistical measure of a relationship between two variables -Correlation does not imply causation: Just because two variables are correlated does not mean that one variable causes the other -Can be either positive or negative. A positive correlation between two variables means that the presence of one variable predicts the presence of the other. A negative correlation means that the presence of one variable predicts the absence of the other -The strength of a correlation is expressed by a number called a correlation coefficient, which ranges from -1 and +1 where =1 is a perfect, negative correlation and +1 is a perfect, positive correlation

Measures of Variability

-A type of descriptive statistical measure that attempts to depict the diversity of the distribution -range, variance, standard deviation -Range (distance between highest and lowest score); Variance is Standard Deviation squared (both essentially relate avg. distance of any score in the distribution from the mean)

Theory

-Aims to explain some phenomenon and allows researchers to generate testable hypotheses with the hope of collecting data that support the theory -Hypotheses often grow out of theories

Operational Definitions

-An explanation of how variables are measured Ex: Two variables need to be o.d-ed in hypothesis "Watching violent television programs makes people more aggressive" 1. What programs will be considered violent? 2. What behaviors will be considered aggressive?

Confounding Variables

-Any difference between the experimental and control conditions, except for the independent variable, that might affect the dependent variable -An experiment allows the researcher to manipulate the independent variable and control for confounding variables

Hawthorne Effect

-Being selected to be in a group of people to participate in an experiment will affect the performance of that group, regardless of what is done to those individuals -Just selecting a sample of people and including them in an experiment will affect the performance of the sample -Control groups help to control for the Hawthorne effect

Normal Curve

-Bell-shaped curve that represents a distribution of scores normally distributed -`68% of scores one st. dev of mean, 95% two st. dev.s, 99% within three standard deviations

Reliability

-Good research is both valid and reliable -Research is reliable when it can be replicated; it is consistent -If the researcher conducted the same research in the same way, the researcher would get similar results -A related concept is validity; Research is valid when it measures what the researcher set out to measure; it is accurate

Validity

-Good research is both valid and reliable -Research is valid when it measures what the researcher set out to measure; it is accurate -A related concept is reliability: Research is reliable when it can be replicated; it is consistent

Survey Method

-Involves asking people to fill out surveys -often used to gather opinions or attitudes and for correlational research -Response rate refers to the proportion of a surveyed group who respond to and return a survey

Double-Blind Procedure

-Method followed such that neither the participants nor the researcher are aware of who is in the experimental or control groups while the experiment is going on -Double-Blind procedures control for both experimenter bias (researchers treating members of the experimental and control groups differently) and participant bias (the tendency for subjects to behave in certain ways based on their perception of an experiment)

Naturalistic Observation

-Research method that involves observing participants in their natural habitats without interacting with them -The goal is to get a realistic and rich picture of the participants' behavior -Cannot establish cause and effect relationships between variables

Basic Research

-Research that explores questions that are of interest to psychologists but are not intended to have immediate, real-world applications -The other category of research is applied research, which is conducted in order to solve practical problems

Statistical Significance

-Scientists have decided that 5% (.05) is cutoff for statistically significant results. This means that in a statistically significant experimental result, there is less than a 5% chance that the results occurred by chance -Researchers use inferential statistics to determine whether results are statistically significant

Inferential Statistics

-Statistics that can determine whether or not findings can be applied to the larger population from which the sample was selected -related to concept of statistical significance: 5% (.05) is cutoff for statistically significant results. This means that in a statistically significant experimental result, there is less than a 5% chance that the results occurred by chance

Participant (Response) Bias

-Tendency for subjects to behave in certain ways based on their perception of an experiment -Can be controlled for using a single-blind procedure (when participants don't know whether they are assigned to an experimental or control group) or a double-blind procedure (neither participants nor researcher know who is in exp/control group during experiment)

Hindsight Bias

-Tendency upon hearing about research findings (etc.) to think that they knew it all along -After an event occurs, it is relatively easy to explain why it happened. The goal of scientific research, however, is to predict what will happen in advance

APA Ethical Guidelines for Human Research

-The APA (American Psychological Association) established ethical guidelines for human and animal research -Any type of academic research must first propose the study to the ethics board or institutional review board (IRB) at the institution -guidelines include: coercion, informed consent, anonymity/confidentiality, lack of risk, debriefing procedures

APA Ethical Guidelines for Animal Research

-The APA (American Psychological Association) established ethical guidelines for human and animal research -Ethical psychological studies using animals must meet the following requirements: have a clear scientific purpose, care for and house animals in a humane way, acquire animal subjects legally, design experimental procedures that employ the least amount of suffering feasible

Population

-The group from which a sample is selected -The population includes anyone or anything that could possible be selected to be in the sample -The goal in selecting a sample is that it represents a larger population

Experiment

-The only research method that can show a causal relationship -Allows the researcher to manipulate the independent variable and control for confounding variables -A confounding variable is any difference between the experimental and control conditions, except for the independent variable, that might affect the dependent variable -Experiments compare at least two groups: an experimental group and a control group that differ based on the independent variable

Assignment

-The process by which participants are put into either an experimental or a control group -Random assignment means that each participant has an equal chance of being placed into any group. It limits the effects of confounding variables based on differences between people -Using random assignment diminishes the chance that participants in the two groups differ in any meaningful way

Experimental Bias

-The unconscious tendency for researchers to treat members of the experimental and control groups differently to increase the chance of confirming their hypothesis -Experimenter bias is not a conscious act. If researchers purposely distort their data, it is called fraud, not experimenter bias -Using a double-blind procedure can eliminate experimenter bias. A double blind occurs when neither the participants nor the researcher are able to affect the outcome of the research

Descriptive Statistics

-Ways of describing a set of data -measures of central tendency are a common descriptive statistic -mean, median, mode

Sampling

-the individuals on whom the research is conducted are called participants/subjects, and the process by which participants are selected is called sampling -To select a sample, first identify the population from which the sample will be selected. The population includes anyone/thing that could possibly be selected to be in the sample. The goal in selecting a sample is that it represents a larger population -Random selection means that every member of the population has an equal chance of being selected. Random selection increases the likelihood that the sample represents the population and that one can generalize the findings to the larger population