Psy 001 Introduction to Psychology: Chapter 2 Methods PDF

Psy 001 Introduction to Psychology Dr. Bobby Hutchison Psychological Sciences University of California Merced Chapter 2: Methods  Psychology as a Science: The Scientific Method Steps involved in the scientific...

Psy 001 Introduction to Psychology Dr. Bobby Hutchison Psychological Sciences University of California Merced Chapter 2: Methods  Psychology as a Science: The Scientific Method Steps involved in the scientific method Identify the Gather problem information Design and Data Generate a conduct analysis hypothesis experiment and s conclusions Repea t Example of the Scientific Method in Psychology Identify the problem Based on observation, previous research, established theory, or Re s e a r c h intuition q u e s t i on n d i t i o n s wi l l at c o Students do not always Under wh cl a s s p repared ud ent s co me t o ities? st d a c t i v come to class prepared with comp le t e with completed activities Example of the Scientific Method in Psychology Gather information Search the literature to see what has been done on the topic Read relevant results for 70–80% what has been done of students do not prepare before class Students do not see how meetings reading before class influences their learning or grades Example of the Scientific Method in Psychology Develop a hypothesis Develop an informed guess based on what you read Have a prediction about how the variables are related Assessments Students Students for points will required to more likely affect complete to read reading assessment for before class before class points Students not Students required to less likely to complete read before assessment for class points  Example of the Scientific Method in Psychology Design and conduct experiment Based on observation, previous research, established theory, or intuition Students take Experimental Readings quiz at Group available beginning of Students earn before class prior to points for Compare class lecture taking quiz student performance Control on quiz Group Students do not earn points for taking quiz Example of the Scientific Method in Psychology Design and conduct Independ Dependen Group ent experiment t Variable Variable Test your hypothesis Experiment Quiz for Points al group points earned on with at least two quiz conditions Control Quiz not Points 1. One Experimental group group for points earned on that receives treatment quiz 2. One Control group that Those students who read doesn’t receive treatment before class should earn more points than those who do not read before class Example of the Scientific Method in Psychology Number of Data analysis and Points on Quiz conclusions See if the data you obtained match your Readin g expected results before class Data might match the hypothesis but do not prove that the Quiz for hypothesis is true Point s Example of the Scientific Method in Psychology Restart the process Think about original problem o Students typically do not prepare for class Replicate and extend results or ask an entirely new question o Ask whether students will prepare for class if they have to answer questions out loud and in class for participation points rather than accuracy points Naturalistic Observation “Watch and learn” Observe behavior without manipulation Most likely representative of real-world behavior No control over behavior Difficult to determine exact cause of behavior Participant Observation Become a member of a group and learn about that group Researcher interacts with population of interest Allows for research insights from participants’ perspective May be subject to biases or interpretation Observations may not be repeatable Case Studies In depth about one person A report of a single person, group, or situation Collect a lot of detail Not an experiment Can be difficult to draw causal relationships between variables Patient Henry Molaison (H.M.) In a case study, you only measure one individual’s behavior but collect a lot of data about that individual Surveys Participants answer standardized questions Questions are used to extract specific information from a group of people o Relatively easy to administer An effective approach to gather lots of information Susceptible to biases from both researchers and participants Ethics Definition Ethics is a set of general principles of how people should be educated, treated, and respected when participating in any study Research Ethics for Human Participants General ethical principles of psychologists Principle A: Beneficence and Nonmaleficence Principle B: Fidelity and Responsibility Principle C: Integrity Principle D: Justice Principle E: Respect for People’s Rights and Dignity The Practice of Ethical Research Institutional review boards, or IRBs, review and assess research proposals based on adherence to general ethical principles: o Study has a sound research design o Minimal and reasonable participant risks associated study o Benefits of study outweigh any potential risks o All participants can make an informed decision to participate in study o Available safeguards protect well-being of participants o All collected data are private and confidential Special Ethical Considerations Potential participants that are not able to legally give informed consent o Includes children under 18 years of age and other individuals of special populations There are two criteria for participation in research that participants must meet: 1. Informed consent from parent/guardian 2. Assent from potential participant Deception The informed consent process may affect participants’ natural behavior or reactions Some experimenters may not reveal the true nature of the study until after participation is complete Deception occurs when experimenters don’t reveal the true nature of the study at the beginning before participation in the experiment Direction and Strength of Correlation Correlations provide two pieces of information about how two variables are related 1. The direction of a relationship between two variables 2. The strength (between 0 and 1.0) of a relationship between two variables Correlations Can BeNumber Misleading of Correlation does not mean Homicid causation es Sometimes a third variable influences both variables of Positive interest correlati on In this case, number of homicides and ice cream sales are related to Ice temperature Crea m Sales Experimental Methods Why we conduct experiments Characteristics of an experiment 1. Manipulate an Test theories through controlled independent variable experiments 2. Randomly assign participants to Establish a cause-and-effect conditions of independent relationship between variables variable 3. Measure behavior Our hypotheses drive our along a dimension experiments The Hypothesis A hypothesis is an “educated Characteristics of a guess” about the outcome of an hypothesis experiment 1. Consistent with prior observation 2. Simple Hypothesis 3. Specific o People who play violent video games 4. Measurable will exhibit more aggressive behavior than people who do not play violent 5. Establish causality video games 6. Falsifiable Experimental Variables Variables Independent Dependent Extraneous Variable Variable Variables What experimenter What participant Uncontrolled changes does events Sample Selection 1. Simple random sample in which everyone has an equal chance of participating 2. Stratified random sample in which individuals are divided into subgroups and take representative samples 3. Non-random sample in which individuals have an unequal chance of participating 4. Convenience sample in which individuals who are accessible are selected Experimental and Control Groups Experimental group Control group 1. The group that the 1. The group that the experimenter is not experimenter conducts conducting an experiment the experiment on on 2. The group exposed to 2. A group that is not influenced by the the manipulated manipulated condition of condition of independent the independent variable variable 3. Used to compare 3. Measure the effect of the experimental results with behavior affected only by independent variable on naturally-occurring dependent variable conditions Experimental and Control Groups Placebo group 1. The group that believes the experimenter is conducting the experiment on them, but the experimenter is not 2. The group exposed to the fake condition of independent variable 3. Measure the effect of participant expectations on dependent variable Placebo effect is when a participant’s expectations but not the independent variable result in a change in the dependent variable Internal Validity/External Validity Internal validity External validity The degree to which results The degree to which results can be attributed to the can be generalized independent variable and not 1. To other people other explanations (e.g., 2. Across settings confounds) 3. Across time Mathematics student grades Chemistry students also improved only after spaced benefit from spaced retrieval retrieval practice; the quizzes practice the following were not easier semester Describing Data: Central Tendency Mode The most frequent value Median The unbiased middle value Mean The average value or center of the dataset skewed by outliers Describing Data: Spread of Data Range Range Varianc Subtract the lowest from the Standar e highest value; i.e., 6’3” – 5’3” d deviatio Variance n The average of squared deviation scores; represents all the values between -3 and +3 standard deviations Standard deviation The spread of data around the mean; 5’3” is -3 standard deviations away from the mean of 5’9” A Brief Introduction to Inferential Statistics Statistics and the 5% rule: If the probability of an event is less than 5%, then we call that a “rare” event This 5% rule gives us a Rare events are depicted in the tails of the guideline to detect distribution differences A Brief Introduction to Inferential Statistics Normal distribution characteristics 1. Symmetrical around the mean 2. Peak is the highest point and mean of the dataset 3. Standard deviation indicates the variability 4. Half of the values lie between 0 and +3 Normal distribution of birth weights standard deviations A Brief Introduction to Inferential Statistics Applying the 5% rule to data 1.64 standard deviations away from the mean represents the most extreme 5% of our data More typical or usual events occur within 1.00 standard deviation of the mean Unusual events are in the most extreme 5% of our data at +/-1.64 standard deviations away from the mean Drawing Conclusions From Data 5’6” The average height of a More unusual man is 5’9” with a standard heights likely come from a deviation of 2” different distribution The cutoff for saying that a score/person comes from this distribution is determined by the 5% cutoff Mean – (1.64 x SD) = 5’6” The population of heights for male Canadians are represented in the distribution Using Statistics In Research We create a prediction based on population characteristics We establish criteria for statistical significance We make decisions about our prediction based on our criteria for statistical significance