Chapter 7 Hypotheticals and You: Testing Your Questions Part III Taking Chances for Fun and Profit

What is a hypothesis? An “educated guess” Their role is to reflect the general problem statement or question that is driving the research Translates the problem or research question into a form that can be tested. An “educated guess” Their role is to reflect the general problem statement or question that is driving the research Translates the problem or research question into a form that can be tested.

Samples and Populations Population The large group to which you would like to generalize your findings Sample The smaller, representative group of the population that is used to do the research Sampling error – a measure of how well a sample represents the population “Generalizability of the sample” Population The large group to which you would like to generalize your findings Sample The smaller, representative group of the population that is used to do the research Sampling error – a measure of how well a sample represents the population “Generalizability of the sample”

The Null Hypothesis Statements that two or more things are equal or unrelated to each other H 0 :  1 =  2 The starting point Accepted as true without knowing more information Benchmark with which actual outcomes are compared Statements that two or more things are equal or unrelated to each other H 0 :  1 =  2 The starting point Accepted as true without knowing more information Benchmark with which actual outcomes are compared

The Research Hypothesis Statement that there is a relationship between two variables Two Types… Nondirectional -- H 1 : X 1 ≠ X 2 Reflects a difference; direction is not specified Two-tailed test Directional -- H 1 : X 1 > X 2 Reflects a difference; direction is specified One-tailed test Statement that there is a relationship between two variables Two Types… Nondirectional -- H 1 : X 1 ≠ X 2 Reflects a difference; direction is not specified Two-tailed test Directional -- H 1 : X 1 > X 2 Reflects a difference; direction is specified One-tailed test

Null & Research Hypotheses

What Makes a Good Hypothesis? Stated in a declarative form rather than a question “Females are taller than males at age 13” Not “Are females taller than males at age 13?” Defines an expected relationship between variables Reflects the theory or literature on which they are based (Google scholar) Brief and to the point Testable – includes variables that can be measured and results than can be statistically verified. Is interesting and NEW knowledge! Stated in a declarative form rather than a question “Females are taller than males at age 13” Not “Are females taller than males at age 13?” Defines an expected relationship between variables Reflects the theory or literature on which they are based (Google scholar) Brief and to the point Testable – includes variables that can be measured and results than can be statistically verified. Is interesting and NEW knowledge!