Research Methods The Scientific Attitude 3 main components

Research Methods

The Scientific Attitude 3 main components Curiosity Skepticism Humility

The Scientific Method A way of rigorously testing ideas against objective observations. Psychology is a science because it uses the scientific method to test ideas empirically.

The Scientific Method Empirical Investigation – The collecting of objective information firsthand by making careful measurements based on direct experience. This is the heart of the testing procedure in the scientific method. To investigate a question “empirically” would mean to collect evidence yourself.

The Goal of Psychological Science? To develop explanations for behavior and mental processes… based on solid EMPIRICAL SCIENCE!

Theories In psychology, theories are explanations for behavior and mental processes. Definition: A testable explanation for a set of facts or observations. Different from a speculation or guess

The Steps of the Scientific Method Step 1: Develop a Hypothesis: A statement predicting the outcome of a scientific study; a statement describing the relationship among variables in a study. “Little Theory”

The Steps of the Scientific Method Step 1: Forming a Hypothesis (Cont. ) Operational definitions – Specific descriptions of concepts involving the conditions of a scientific study. Must be included in the hypothesis. Used to check researcher bias. Also allows others to REPLICATE the study

The Steps of the Scientific Method Step 2: Performing a Controlled Test Hypothesis must undergo a controlled test to determine whether it passes or fails. Independent Variable – Condition that the experimenter changes independently of all the other carefully controlled experimental conditions. The STIMULI you are studying. Random Presentation must also occur. Change independent variable randomly so it is unpredictable.

The Steps of the Scientific Method Step 3: Gathering Objective Data- Information gathered by direct observation. Dependent Variable – The measured outcome of a study; the responses of the subjects in a study. Comes from the assumption that the responses of participants in an experiment depend directly on the conditions to which they have been exposed. The RESPONSE made by the participants in the experiement.

The Steps of the Scientific Method Step 4: Analyzing the Results and Accepting or Rejecting the Hypothesis. Pretty self explanatory right? ? ? Have to take into consideration the probability of right answers when guessing…

The Steps of the Scientific Method Step 5: Publishing, Criticizing, and Replicating the Results. Often, people try to publish scientific research, but before being published it must be critiqued and criticized by experts. Fewer than 2% of papers on psychological research submitted to journals actually get into print without major revisions. Some critics who are on the fence may attempt to replicate the experiment.

Types of Psychological Research Experimental Method – Used to determine Cause and Effect! Develop a research question Survey the literature (helps for hypothesis) Form Hypothesis Establish Independent Variable (Part that changes) Establish Dependent Variable (The measured outcome of a study; the responses of the subjects in a study) Confounding or Extraneous Variable (Other things that can affect the outcome).

Types of Psychological Research Experimental Method (Cont. ) Ensure Controls (Ensure all groups in the experiment are treated exactly the same). Choose Sampling / Subjects (Must be random to represent population). Procedure Results / Statistics Discussion

Control Group vs. Experimental Group Control Group – Serves as a standard against which other groups can be compared. Experimental Group – The group that is manipulated by variables in an experiment.

Types of Psychological Research Non Experimental Method Lack the control of Experimental Research Methods. Used in situations where it may be unethical to conduct true experimental research. Ex. – Cancer research. Ex Post Facto – Research in which we choose subjects based on a pre-existing condition.

Types of Psychological Research Correlational Studies Mainly statistical in nature. Determine the relationship (or correlation) between 2 variables. Example – People who smoke are more likely to get lung cancer. Use something called the CORRELATION COEFFICIENT to summarize the relationship between 2 variables in an experiment.

Types of Psychological Research Correlational Studies (Cont) Correlation Coefficient Can range from a negative number as low as -1. 0 to a positive number as high as +1. 0. Positive Correlation Negative Correlation Zero Correlation

Types of Psychological Research Correlational Studies (Cont. ) Zero Correlation = No relationship between the variables. Example GPA. – There is a zero correlation between shoe size and

Types of Psychological Research Correlational Studies (Cont. ) Positive Correlation – Variables show a relationship in which they vary in the same direction (as the values of one variable increase, so do those of the other). Example – There is generally a positive correlation of about +0. 4 between SAT scores and college grades.

Types of Psychological Research Correlational Studies (Cont. ) Negative Correlation – Variables show a relationship in which they vary in the opposite direction (as the value of one variable goes up, the value of the other variable goes down). Example – A correlational study on anxiety shows a correlation of -0. 7 between anxiety and time spent studying. In other words, more study is associated with less anxiety. A negative correlation can still indicate a very strong relationship.

Types of Psychological Research Surveys A quasi-experimental method in which questions are asked to subjects. Questions answer. cannot be skewed or biased toward a particular

Types of Psychological Research Naturalistic Observation Subjects are observed in their natural environment. Much less control in this Key: Must be sure subjects are not aware they’re being observed.

Types of Psychological Research Longitudinal Study One group of subjects is followed and observed for an extended period of time. Good for investigating the long range effects of something.

Types of Psychological Research Cross-sectional Study in which representative cross section of the population is tested or surveyed at one specific time. Cohort-sequential Study in which a cross section of the population is chosen and then each cohort is followed for a short period of time. Both are similar to longitudinal studies.

Bias in Research Personal Bias The researcher allowing personal beliefs to affect the outcome of a study.

Bias in Research Expectancy Bias The researcher allowing his or her expectations to affect the outcome of a study.

Combating Bias in Research Double – Blind Study An experimental procedure in which both researchers and participants are uninformed about the nature of the independent variable being administered. Placebo involved to keep participants and researchers from forming bias.

Ethics in Research Institutional Review Board – Group that reviews and approves all research to ensure no ethical violations take place. Deception – Allowed under certain circumstances. Participants must be debriefed afterward. Animal Research Studies

Organizing Research Data Descriptive Statistics Statistical procedures used to describe characteristics and responses of groups of subjects.

Organizing Research Data Descriptive Statistics Measure of Central Tendency AKA – Averages Help us locate the center of a set of measurements.

Organizing Research Data Descriptive Statistics Measure of Central Tendency has 3 forms Mean – The measure of central tendency most often used to describe a set of data – calculated by adding all the scores and dividing by the number of scores. Can be distorted by extreme scores.

Organizing Research Data Descriptive Statistics Measure of Central Tendency has 3 forms Median – A measure of central tendency of distribution, represented by the score that separates the upper half of the scores in a distribution from the lower half. The middle score. Not distorted by extreme scores.

Organizing Research Data Descriptive Statistics Measure of Central Tendency has 3 forms Mode – A measure of central tendency for a distribution, represented by the score that occurs more often than any other. Not effective when test groups are small.

Organizing Research Data Descriptive Statistics Measures of Variability Allows us to know how well the average represents the distribution as a whole. That is, do most of the scores cluster closely near the average or are they spread out widely. Low Variability = All scores close to the average. High Variability = Scores widely spread out.

Organizing Research Data Descriptive Statistics Measures of Variability Range – The simplest measure of variability, represented by the difference between the highest and the lowest values in a frequency distribution. Standard Deviation – A measure of variability that indicates the average difference between the scores and their mean. The larger the score the more spread out they are. The smaller the score the closer together they are.

Organizing Research Data Inferential Statistics Statistical techniques used to assess whether the results of a study are reliable or whether they might be simply the result of chance. Often used to determine whether two or more groups are essentially the same or different.

Organizing Research Data Inferential Statistics To ensure accurate statistics must be sure samples are selected in an unbiased manner. Random Sample – Sample group of subjects selected by chance. Not always practicable. Representative Sample – A sample group obtained in such a way that it reflects the distribution of important variables in the larger population in which the researchers are interested. Age, income, ethnicity, and location all considered.

Organizing Research Data Inferential Statistics Significant Difference – Psychologists accept a difference between the groups as “real, ” or significant, when the probability that it might be due to an atypical sample drawn by chance is less than 5 in 100. Indicated by the notation p<. 05.