Report

Chapter 2: Research Methods Dr. Mary Streit Suffolk Community College Chapter 2 – Research Methods Goal of Research: to find the truth! What is really going on?? How can we conduct research to get at the truth? 1. Adhere to the scientific method 2. Make sure your study is falsifiable or subject to replication. Include operational definitions. 3. Propose a theory that is parsimonious or not overly complicated. Keep it simple whenever possible. Chapter 2 – Research Methods Two major categories or types of research: Basic - laboratory setting - Theory building Applied - field or real-world setting - solve a problem Chapter 2 – Research methods Two types of research methods: 1. Non-experimental. - hands-off: no control - real-world setting 2. Experimental. - hands-on: control - laboratory setting Which category seems most similar to applied research? Basic research? Chapter 2 – Research Methods Non-Experimental Research Methods. 1. Naturalistic observation. - AKA observational research - meets first goal of psychology – Description - answers the question “What?” - qualitative - operational definitions & hypotheses emerge -Jane Goodal and Chimpanzees -Dian Fossey and Gorillas Chapter 2 – Research Methods Limitations: - lengthy and time-consuming - observer bias: AKA experimenter bias. When the researcher is biased in his/her observations – usually in the direction that supports his/her hypothesis. - observer effect / reactivity: When people behave differently when they know they are being watched or observed. Chapter 2 – Research Methods Non-Experimental Research Methods [cont’d] 2. Case study. - A detailed description of an individual with a rare or unusual disorder - In-depth analysis - Can be used to describe and explain behavior - Limitations: results can not be applied to the general population - Memory problems - Famous cases: patient H.M., Phineas Gage, Genie “the wild child” - For more information on Genie’s case see: http://www.psychology.sbc.edu/cesarz.htm Phineas Gage for more info: http://www.deakin.edu.au/hmnbs/psychology/gagepage/ Patient H.M. For more information on H.M., see the link below: http://thebrain.mcgill.ca/flash/capsules/pdf_articles/patient_hm.pdf Chapter 2 – Research Methods Non-Experimental Research Methods. Surveys. - questionnaires that allow psychologists to measure covert behaviors: attitudes, opinions, values, beliefs, etc. - can be easily used to measure large groups of people - more quantitative - can be used to describe, explain, and even predict behavior Chapter 2 – Research Methods Chapter 2 – Research Methods Non-experimental Research Methods. Surveys. - population: everyone (the entire pizza pie) - sample: not everyone or a subset of the population( a slice of the pie) You want your sample to be representative of the population. Why? So you can generalize your results to the population. (e.g. - You don’t have to eat the entire pizza pie to see how it tastes. You can just eat one slice!) Chapter 2 – Research Methods Non-Experimental Research Methods [continued] 3. Survey limitations - Sample bias: when your sample is different from the population - Example: When you happen to eat the only slice in the entire pie that is pepperoni. This is problematic if you erroneously assume that the rest of the pie is also pepperoni. - Sample results can NOT be generalized to the population - 1934- Literary Digest. Al Landon vs. FDR: famous case of sample bias. Sampled all US citizens with phones. - Random samples eliminate sample bias - Random sample: when every element in the population has an equal chance of being selected into the sample. - Lotto number drawings Chapter 2 – Research Methods Chapter 2 – Research methods If you are interested in finding out how many hours per week the average full-time college student in the US studies, what would be your population? Your sample? Which study would you prefer to do? Why? Chapter 2 – Research methods Non-experimental Research Methods [cont’d] Survey limitations - social desirability: When people change their actual attitudes, values, beliefs, etc. in order to please the experimenter and/or to appear politically correct. In other words, when people lie on a survey to make themselves look or feel good. - anonymous responses – helps to eliminate this problem somewhat - teen survey of sexual activity by the National Institute of Health in 1997 vs. 2000. Huge increase in abstinence reported. Why?? Chapter 2 – Research Methods Non-Experimental Research Methods. 4. Correlational research. - examines the relationship between two variables as they occur naturally - hands-off - no experimenter manipulation or control - real world data - heavily quantitative - correlation coefficient (r2) - frequently used to predict behavior Chapter 2 – Research methods Non-Experimental Research Methods. Correlation coefficient. - A number with a range of -1.0 and +1.0 that expresses numerically the relationship between two variables. - The sign of the number indicates the direction the two variables are moving in relation to each other - A positive correlation means both variables are moving in the same direction (e.g. – temperature outside and # of ice cream cones consumed) - A negative correlation means both variables are moving in opposite directions (e.g. – temperature outside and the number of layers of clothing) Chapter 2 – research methods Non-experimental research Methods. Correlation coefficient (cont’d). - The number itself represents the strength of the relationship. The closer the number is to 1.0, regardless of the sign, the stronger the relationship. - For example, which number represents the strongest correlation coefficient? a. b. c. d. -.72 +.63 -.56 +.49 Chapter 2 – Research Methods Non-experimental Research Methods. Correlation coefficients. What do the numbers mean? Say you have 2 variables: height and IQ, and you want to find out if there is a relationship between these two variables. Because you can NOT control an individuals height or IQ, you decide to do correlational research. Chapter 2 – Research Methods - If you have a perfect +1.0 correlation, it means that for every 1” increase in height, you will see a 1 point increase in IQ. In other words, there is a perfect 1 to 1 correspondence. - If you have a +.90 correlation, it means that for every 1” increase in height, you will see a +.90 increase in IQ. - If you have a +.80 correlation, it means that for every 1” increase in height, you will see a +.80 increase in IQ. - What about a negative correlation coefficient? See if you can figure out what would happen in the above examples if the numbers were negative instead of positive? Chapter 2 – Research Methods Non-Experimental Research Methods [cont’d] 4. Correlational research Limitations. - correlation does NOT mean causation!!! - Why do we get colds more frequently in the winter months? Is it because it is cold outside? What is really going on? - in correlational research, there is a lack of experimenter control over other factors - these other factors are called: extraneous variables, third variables or confounds - only in experimental research can we conclude that there is a cause and effect relationship - by controlling for other factors Chapter 2 – Research Methods The human sneeze can travel at speeds well beyond 100 mph and can reach as far as 30ft Non-Experimental Research Methods: Matching Review 1. 2. 3. 4. 5. 6. 7. 8. 9. an in-depth analysis of a single individual or subject used to measure the covert behaviors of many people subject to the problem of observer bias when people behave differently when they know they are being watched when people lie on a survey in order to look good to the researcher when the experimenter intentionally looks for a behavior to occur when the people in your sample are different from the population The entire group of people that you are interested in studying A method used when you are trying to determine the relationship between two variables that you can not control a. Observer bias b. Observer c. d. e. f. g. h. i. j. effect Sample Population Sample bias Social desirability Survey Case study Naturalistic observation Correlational research Non-Experimental Research Review 1. 2. 3. 4. 5. 6. 7. 8. 9. A relationship between two variables where one variable increases as the other decreases A relationship between two variables where one variable increase as the other increases A detailed description of behaviors observed in their naturally occurring environment A subset of the population factors that were not controlled for that may be causing the effect observed When every element in the population has an equal chance of being selected into the sample its main limitation is that the results can not be generalized to the entire population A type of research used to solve a problem in the real world A type of research used to build a theory a. Observational b. c. d. e. f. g. h. i. j. research Sample Population Confounds Random sample Case study Basic research Applied research Positive correlation Negative correlation Chapter 2 – Methods Experimental Research. - Typically conducted in a laboratory setting - Does not occur in the real world - Experimenter has control over outside factors or confounds - Experimenter intentionally manipulates or changes factors - Hands-on: experimenter manipulates and controls variables in the study. Chapter 2 - Methods There are two types of variables in experimental research: 1. Independent variable (IV): the variable that is intentionally changed or manipulated by the researcher. [the cause] - sometimes you have different levels of the independent variable. For example, the milligram levels of a new drug. 2. Dependent variable (DV): the variable that is used to measure any change. [the effect] Chapter 2 – Research Methods - In experimental research, any change in the DV is seen as a direct result of the IV due to experimenter control - Potential confounds are controlled for - The independent variable usually precedes or comes before the dependent variable in time. Chapter 2 - Methods Typically, there are at least two groups of subjects in experimental research: 1. Experimental group. This is the group of subjects who receives the independent variable that you are most interested in. 2. Control group. This is the group of subjects who do NOT receive any form of the independent variable. The control group is the standard to which all other groups are compared. Control groups allow researchers to rule out confounds In a well-designed study, subjects are randomly assigned to either the experimental or control group Chapter 2 – Methods Assignment: Labeling variables In each example, label the IV, the DV, the experimental group and the control group. If a control group is lacking, add one to the study. 1. Researchers are interested in the effects of violent TV on aggressive behavior in children. 100 Children in 2nd grade are randomly assigned to watch a video. Half of the children are shown a ½ hour video of Barney, and the other half of the children are shown a ½ hour video of the Power Rangers. After the videos are shown, all children are given a ½ hour of recess. Any violent or aggressive behavior is recorded. Chapter 2 - Research Methods 2. 3. Researchers are interested in the effects of testosterone on violent and aggressive behavior. Male rats are given injections for 1 month of the following: 10 mg of a saline solution, 10mg of testosterone, 20 mg of testosterone, or no injections at all. Any violent or aggressive behaviors were noted. Researchers are interested in the effects of a new drug on children with ADHD and their ability to pay attention in the classroom. 200 ten year old boys with ADHD were randomly assigned to one of four conditions: no drug, placebo drug, 10mg of new drug, and 10mg of ritalin (the drug that has often been used to treat ADHD). Their ability to pay attention in the classroom was measured after the drugs were administered. Chapter 2 - Methods Read the paragraph below and then see if you can answer the following questions: Researchers are interested in whether or not smoking marijuana causes an increase in appetite. 100 subjects are randomly assigned to smoke either a marijuana cigarette, or a regular nicotine cigarette. After the subjects finish smoking, they are given a gallon of vanilla ice cream, and told that they can eat as much ice cream as they would like. The # of grams of ice cream consumed is their measure of appetite. What is the IV in this study? The DV? Chapter 2 – Research Methods - Results: Subjects who smoked marijuana ate significantly more ice cream than those who smoked the regular nicotine cigarette. - Can you conclude with confidence that smoking marijuana led to an increase in appetite? - What other potential confounds could be at work here? Chapter 2 – Research Methods Potential confounds: - Lactose intolerant - Gender (Male/Female) - When the subject last ate - How much the subject likes ice cream What if all confounds are controlled for. Can you then conclude with confidence that smoking marijuana leads to an increase in appetite? Chapter 2 - Assignment Critical Thinking Assignment#1: select three articles from the links below and see if the headline is true or false based on the actual study described in the article. 5 pages minimum APA style. Be sure to include: A brief summary. What type of research method was used in each study? Was it experimental? If yes, label any variables: IV? DV? Experimental group? Control group? Etc. Was is non-experimental? If yes, which non-experimental method was used? What was the sample? How was the sample selected? Was it random? For all studies, what were the conclusions? Do you agree with their findings? What are some potential confounds? Type this up, and hand it in for credit for your paper. Assignment #1 links 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. Music lessons improve kids' brain development, memory Authoritarian parents have fat kids Chocolate really does make us feel better Anorexia largely determined by heredity Soda causes obesity, researchers assert Spanking children fuels aggression, anxiety Eating pizza cuts cancer risk Breastfeeding fights arthritis Church attendance is good for your health Video games increase aggression Higher beer prices cut gonorrhea rates Early unsolicited sexual encounters leads to a life of crime "Wash Your Hands" signs only work for women Luckiest people born in the summer ANY type of TV program harms toddlers Snooze or lose: memory retention enhanced by sleep Research Methods – just for fun Funny article to read about correlation and causation. Correlation and causation