Statistics for Psychology Introduction Overview and Homework 1 Questions Modules 1 and 2, pp. 355-356 Introduction, Psychological Science Three Basics, Intro With Chi Square, Quick Summary

Introductory Material 1. Introduction Remain calm, What are statistics? Why are they necessary? 2. Psychological Science Psychology and science with their definitions and goals, The four essential pieces of science over four steps 3. Three Intro Basics Variables, Summation sign, Probability 4. Introduction to the whole process with chi square  Read carefully the more detailed information in the book titled An Introduction to Research Methods in Science pp. 4-11

The answer in steps would be: 22 = 4 (exponents first) 1. What is the order of mathematical operations? Find the answer for 2(2+22-4)/2. Parentheses first, then exponents, then multiplication and division, and then addition and subtraction. Sometimes this is abbreviated by ‘pemdas’. The answer in steps would be: 22 = 4 (exponents first) 2+4 = 6 and then 6-4 = 2 (parentheses) 2x2 = 4 (multiplication) 4/2 = 2 (division)

They are often mathematical in nature and standardized. 2. What are statistics? Statistics are methods for organizing, summarizing, evaluating, and communicating information. They are often mathematical in nature and standardized. They are tools, a means to an end. The end result is to build knowledge with one’s statistical tools.

3. Why are statistics important? Statistics are important because they allow one to do scientific research, to understand scientific research, to be up to date and knowledgeable in one’s profession, and to be capable of making good choices about information in one’s personal life. Additionally, in the four steps of scientific research, one cannot get from step three to step four without them, and step four is very much the whole point of doing the research in the first place.

It is a vast field that is 4. What is the definition of Psychology, its goals, what holds the vast field together, and what does integration with the other sciences mean? Psychology is the scientific study of behavior, both internal and external, with the goals of describing, predicting, and explaining behavior. It is a vast field that is held together by its subject matter, goals, and methods. Finally, not only must all of psychology fit together with its many areas, but all its findings must fit together with other things that are known about the world from the other sciences and fields of knowledge.

5. What is science and what are its goals? Science is a method for getting knowledge, and the overall goals are to find what exists and the rules for how it works. More specifically, the goals are to describe, explain, and predict whatever is being studied.

6. Name and define the four essential tools that science uses. (1) A theory is a collections of statements that describes and explains something. It is usually somewhat verified from past research. Theories and their parts must, at least in principle, be testable. It is also a story one tells about empirical observations that are collected: it is the glue that holds facts together into something comprehensible. (2) A hypothesis is sometimes referred to as a statement that describes and explains something, but it is not as well verified as a theory. As well, a hypothesis is often simply a falsifiable prediction about the relationship between two variables.

6. Name and define the four essential tools that science uses. (3) Empirical observations are verifiable direct observations, that is, they are direct measurements that can be replicated by others. (4) The last one is really a two-part piece. Healthy skepticism means that one is always questioning whether or not everything has been done right and makes sense, as well as thinking about what other things could be the reason for one’s results, and the idea that researchers need to convince others they are correct. Healthy ethics refers to following the APA ethical guidelines, any IRB guidelines, and generally using common sense in treating both human and non-human participants.

7. What are the four steps of research? 1. Get yourself a testable prediction from a theory or hypothesis 2. Design a study and make observations to test the prediction 3. Statistically describe and evaluate the observations 4. Make conclusions and integrate them back into the original theory or hypothesis.

7a. What is a representative sample? A representative sample is a sample that has all the important characteristics of the population, except that it is smaller in number. Since we cannot normally test populations, we test samples instead, and then generalize our results to the population. However, if the sample is not representative, generalization cannot be done.

7b. What are the two basic study design options and their pluses and minuses? The basic designs are experimental designs, which are explanatory, and non-experimental designs, which are descriptive or predictive. (1) Experimental designs allow for suggesting cause and effect by changing only one thing and then observing what happens. The thing you change is the independent variable, the thing you observe is the dependent variable. (2) Non-experimental designs cannot show cause and effect as there is no experimental manipulation ~ you are just observing of measuring something. However, they may be able to get a better look at more naturalistic behavior and they may be the only option due to ethical, resource, or other considerations.

7c. What are the two branches of statistics and what do they do? There are descriptive and inferential statistics. Descriptive statistics are used to find patterns in information by organizing and summarizing the information. Inferential statistics are used to evaluate the patterns that are found to be reasonably confident that they are not due to chance. Both branches of statistics are used to communicate statistical results and information: descriptive statistics communicate the patterns while inferential statistics communicate the evaluation of those patterns.

7d. Why are there no neutral statistics? All statistics involve choice. That is, the researcher chooses what statistics to use to look for patterns and evaluate their data, and then they also choose what statistics to present to others to communicate their findings.

7e. What does a single study on some topic tell about that topic? One study on a topic is suggestive, but more studies must be completed that replicate and expand on the study before one can reasonably trust that something is true.

There are at least three overall ways of labeling variables. 8. What are the various ways of labeling variables? Give an example of each. Also, what is an operational definition? There are at least three overall ways of labeling variables. 1. One distinction is between quantitative variables (the magnitude is measured with numbers: more ‘how much’) and qualitative variables (do not lend themselves to measurement in terms of numbers: more ‘what’). Time spent driving to work would be a quantitative variable, whereas the thoughts and feelings you had while driving would be more qualitative.

8. What are the various ways of labeling variables 8. What are the various ways of labeling variables? Give an example of each. Also, what is an operational definition? 2. Another distinction is between continuous variables (those with quantities in between) and discrete variables (they are either this or that, they do not have in-betweens). Weight in pounds is a continuous variable (one can weigh 150 ½ pounds). Names of people or number of children would be a discrete variable (you cannot have a Fred and a half, or 3.4 children). Discrete variables that are completely either/or, that can have only one of two values, like on/off, are called dichotomous variables.

Nominal scale = identity only, such as names 8. What are the various ways of labeling variables? Give an example of each. Also, what is an operational definition? 3. Distinctions between variables can also be made by labeling them on the scales of measurement. Nominal scale = identity only, such as names Ordinal scale = identity + magnitude, such as places in a race Interval scale = identity + magnitude + equal unit size, such as Fahrenheit temperature scale Ratio scale = identity + magnitude + equal unit size + absolute zero, such as height in inches or the Kelvin temperature scale

8. What are the various ways of labeling variables 8. What are the various ways of labeling variables? Give an example of each. Also, what is an operational definition? Finally, operational definitions are definitions of a variable in terms of the operations (activities) used to measure or manipulate it. For example, an operational definition of happiness might be a score of 8 or higher on a mood scale.

9. What is the summation sign and what does it do 9. What is the summation sign and what does it do? If x = 2, 4, 4, 4, 4, then what does Σx equal? Σx2? The summation sign is a mathematical abbreviation that more or less means, sum up all the stuff that comes after it. It is a shorthand for doing a specific series of additions. The answer to the first summation question would be to add up all the numbers identified as x to equal 18. The answer to the second question requires one to square each number first, and then add them all up, to equal 68.

10. What does probability mean? Probability refers to how likely something is to happen. Probabilities are always numbers from zero to one, where a zero means no likelihood of happening (whatever it is will definitely not happen) and a one means absolute likelihood of happening (whatever it is will definitely happen).

11. Find the probabilities for the following cases: a) Getting a heads on one coin toss? b) Getting a 2 on the roll of one six-sided die? c) Drawing a King of Hearts from a 52 card deck? d) Drawing any King from a 52 card deck? In order to answer these questions you needed to plug the information into the probability formula below. (a) 1/2 = .50 (b) 1/6 = .167 (c) 1/52 = .019 (d) 4/52 = .077 Number of specific outcomes Number of possible outcomes p (something) =

a. Do you prefer the color red or blue? 12. Find out if the following data are statistically significant based on a critical value of 3.84. a. Do you prefer the color red or blue? Red Blue 10 12 Not statistically significant c2 = + = .18 ( 10 – 11 )2 11 ( 12-11 )2 b. Do you like bright light or dim? Bright Dim 40 30 Not statistically significant c2 = + = 1.43 ( 40 – 35 )2 35 ( 30-35 )2

c. Which would you prefer to eat? 12. Find out if the following data are statistically significant based on a critical value of 3.84. c. Which would you prefer to eat? Pizza Cabbage 50 10 c2 = + = 26.67 ( 50-30 )2 30 (10-30 )2 Statistically significant d. What kind of pet do you prefer? Llama Hippo 20 22 Not statistically significant c2 = + = .095 ( 20-21 )2 21 ( 22-21 )2