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A research hypothesis gives direction to the research process.
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Idea: Collect data to determine whether the null hypothesis can be rejected in favor of the research hypothesis.

**Purposes of the hypothesis in quantitative research**- Bringing information together to enable the researcher to make a tentative statement about how the variables in the study may be related
- Stimulating a research endeavor that results in the accumulation of new knowledge
- Providing the investigator with a relational statement
- Providing direction to the research
- Providing a framework for reporting the findings and conclusions of the study

**What is a research hypothesis?**- A hypothesis is a statement or proposition set forth as an explanation for the occurrence of some phenomenon.
- A research hypothesis is such a statement proposed to explain or answer a research question.
- A research hypothesis typically describes an expected difference in variables across groups, a change in variables (through time or otherwise), or an expect of one or more variables on one or more response variables.
- It gives a prediction for the relationship(s) among the variables from the research question.
- Example: The mean high school GPA is higher for students whose parents graduated from college than it is for students whose parents did not graduate from college.

- Research hypotheses can be categorized as directional or non-directional
- A directional hypothesis specifically quantitative the direction of the proposed difference / change / expect.
- Example: Higher doses of a current anti-depressant cause blood pressure to decrease.

- A non-directional hypothesis does not quantify the direction of the proposed difference / change / expect.
- Example: There is a difference in typical participation in college

**Why construct a research hypothesis**

- Provides a testable statement for the researcher
- Provides a framework for explanations and conclusions of the study
- Provides a clear indication of the intention and utility for the audience

**Suggestions for deriving hypotheses**

**Inductive hypothesis**: To formulate a hypothesis as a generalization**from apparent observed relationships****Deductive hypothesis**: To deduct a hypothesis as a generalization**from existing theories**

**Characteristics of Hypothesis****Clarity (One relationship at a time)**- An effective research hypothesis makes clear the expected relationships between variables.
- Example: Parental involvement in school is associated with an increase in GPA. (Good)

**Testability**- An effective hypothesis can be tested through observation.
- Often this requires operational definitions of constructs outside the hypothesis itself.
- Example: A daily dose of Ritalin will increase signs of attentive behavior more than a daily placebo. (Good)

**Consistency**- An effective hypothesis represents a consistent extension of current knowledge.
- Example: Male high school students respond poorly to group exercises because they cannot develop empathy. (Not Good)

**Simplicity**- An effective hypothesis is stated as simply as possible.
- State the variables of interest and a proposed relationship.
If multiple relationships are suspected, state multiple hypotheses

**Types of hypotheses**

**Research Hypothesis**- A hypothesis from observation, the literature, and/or the theory in the study
- A research hypothesis states the relationship one expects to fine as a result of the research

**Null Hypothesis**- A statistical hypothesis is the same as the null hypothesis, because it states that there is no relationship between the variables in the study
- A Null Hypothesis is a hypothesis corresponding to the research hypothesis that proposes no relationship is present.
- Null hypotheses are not reported in research proposals or final conclusions
- Null hypotheses do not represent an expected outcome
- The null hypothesis and research hypothesis are mutually exclusive
- The null hypothesis is never accepted!!!

**Alternative Hypothesis**- This hypothesis explains what the alternative hypothesis is.
- "Children taught by individual instruction will exhibit less mastery of mathematical concepts than those taught by group instruction."
- For the purposes of statistical testing, the research hypothesis is often referred to as the alternative hypothesis, denoted H1 or Ha
- Example: Do males and females participate in academic extracurricular activities at different rates?
- H0: Males and females participate in academic extracurricular activities at the same rate.
- Ha: Males participate in academic extracurricular activities at a lower rate than females.

**Testing the hypothesis**

Reject the null in favor of the alternative only if the observed evidence is suciently strong that the unusual observations cannot be due to chance

- State the expected relationship(s) among variables, the research hypothesis
- State the corresponding null hypothesis
- Select an experiment that will have an expected outcome
**if the null hypothesis is true** - Collect and analyze data
- If the data are sufficiently unusual according to expectations, reject the null hypothesis in favor of the alternative hypothesis

**Quantitative research plan**

**Problem****Hypothesis****Methodology****Data collecting****Data analysis**

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