Research Methodology - Hypothesis Testing
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Questions and Answers

Which statistical tests rely on assumptions about the population distribution?

  • Permutation tests
  • Non-parametric tests
  • Bootstrap tests
  • Parametric tests (correct)
  • What is a key characteristic of non-parametric tests?

  • They are always more powerful than parametric tests
  • They can only test for means
  • They do not assume a specific distribution (correct)
  • They require a large sample size
  • Which factor is not considered when selecting a probability distribution for hypothesis testing?

  • The population size (correct)
  • The purpose of the test
  • The type of test (one or two-tailed)
  • The level of significance
  • What is the purpose of comparing the test statistic to the critical value?

    <p>To accept or reject the null hypothesis</p> Signup and view all the answers

    Which of the following is a primary source of hypotheses according to the provided information?

    <p>Cultural traditions</p> Signup and view all the answers

    Which type of hypothesis test assumes that the data comes from a normally distributed population?

    <p>Parametric tests</p> Signup and view all the answers

    What is a primary characteristic of a non-parametric test?

    <p>Used when sample sizes are small and non-normal</p> Signup and view all the answers

    Which of the following is NOT considered a parametric test?

    <p>Mann-Whitney test</p> Signup and view all the answers

    Which test is specifically used to compare two independent samples?

    <p>Two-group T-test</p> Signup and view all the answers

    What condition must be met to use a Z-test effectively?

    <p>Population variance is known</p> Signup and view all the answers

    Which non-parametric test is used for comparing paired samples?

    <p>Wilcoxon signed-rank test</p> Signup and view all the answers

    What is the main difference between parametric and non-parametric tests?

    <p>Non-parametric tests do not assume a specific population distribution</p> Signup and view all the answers

    Which of the following tests is appropriate for analyzing differences across multiple independent samples?

    <p>ANOVA</p> Signup and view all the answers

    When should a t-distribution be used instead of a normal distribution in hypothesis testing?

    <p>When the sample size is small and population variance is unknown</p> Signup and view all the answers

    What is the consequence of rejecting the null hypothesis when it is actually true?

    <p>Type I error</p> Signup and view all the answers

    Which step is NOT part of the hypothesis testing process described?

    <p>Collecting qualitative data</p> Signup and view all the answers

    In a two-tailed hypothesis test, the value for α when comparing calculated probability must be:

    <p>Half of α</p> Signup and view all the answers

    What does it mean if the calculated probability is greater than the level of significance (α)?

    <p>Accept the null hypothesis</p> Signup and view all the answers

    What risk is associated with accepting the null hypothesis?

    <p>Committing a Type II error</p> Signup and view all the answers

    Which is a correct sequence of steps in hypothesis testing?

    <p>Set significance level, decide distribution, random sampling, calculate probability</p> Signup and view all the answers

    Why is random sampling important in hypothesis testing?

    <p>It ensures the sample reflects the population</p> Signup and view all the answers

    What statement accurately describes the significance level (α)?

    <p>It is a threshold to determine Type I error probability</p> Signup and view all the answers

    What is the overall goal of hypothesis testing?

    <p>To determine if there is enough evidence to reject the null hypothesis</p> Signup and view all the answers

    Which test is appropriate for judging the significance of means in small samples when the population variance is unknown?

    <p>T-test</p> Signup and view all the answers

    What does the chi-square test primarily compare?

    <p>Sample variance to a theoretical population variance</p> Signup and view all the answers

    In what scenario is the paired T-test used?

    <p>When judging the mean of differences between two related samples</p> Signup and view all the answers

    Which test would you use to assess the significance of the correlation coefficient?

    <p>T-test</p> Signup and view all the answers

    What is the primary distribution associated with the F-test?

    <p>Chi-square distribution</p> Signup and view all the answers

    When should the Z-test be used over the T-test?

    <p>When the sample size is large and population variance is known</p> Signup and view all the answers

    Which test can be used for analysis of variance (ANOVA)?

    <p>F-test</p> Signup and view all the answers

    Which of the following is a characteristic of parametric tests?

    <p>They require certain assumptions about the population parameters</p> Signup and view all the answers

    Which statistical method primarily focuses on comparing the variance of two independent samples?

    <p>F-test</p> Signup and view all the answers

    When is a Z-test typically used?

    <p>When testing the significance of proportions in large samples</p> Signup and view all the answers

    Which non-parametric test is specifically designed for analyzing matched pairs?

    <p>Wilcoxon matched pairs test</p> Signup and view all the answers

    Which of the following tests can be utilized to compare two independent samples?

    <p>Wilcoxon Mann-Whitney test</p> Signup and view all the answers

    Which of the following statements about the Kruskal-Wallis H-test is true?

    <p>It is an analysis of variance for non-parametric data.</p> Signup and view all the answers

    Which method is primarily used to determine the degree of association among multiple sets of ranked data?

    <p>Kendall's coefficient of concordance</p> Signup and view all the answers

    What is a critical requirement for conducting a sign test?

    <p>The data must contain ordinal or nominal scales.</p> Signup and view all the answers

    In which scenario would the McNemar test be most appropriately applied?

    <p>Evaluating the change in opinions in two related samples.</p> Signup and view all the answers

    Which non-parametric test would be the most appropriate for assessing the correlation between variables?

    <p>Rank correlation method</p> Signup and view all the answers

    What distinguishes the Wilcoxon Mann-Whitney test from the Sign test?

    <p>The Wilcoxon test considers both direction and magnitude of differences.</p> Signup and view all the answers

    Which of the following is NOT a characteristic of non-parametric tests?

    <p>They are always less powerful than parametric tests.</p> Signup and view all the answers

    Study Notes

    Research Methodology - Hypothesis Testing

    • Hypothesis is a key instrument in research, suggesting experiments and observations. Many experiments are deliberately designed to test hypotheses.
    • Decision-makers often use hypothesis testing based on available data, before making a decision in social sciences.
    • Hypothesis testing is a strategy for deciding if sample data supports generalization about population parameters.
    • A hypothesis may not be definitively proven but is accepted if it withstands critical testing.

    What is a Hypothesis?

    • A hypothesis is a tentative assumption or supposition that's tested or disproved.
    • It's a formal question to be resolved, explaining the occurrence of phenomenon, or an explanation supported by existing evidence.
    • A research hypothesis is a predictive statement about an independent variable and a dependent variable.

    Types of Hypotheses

    • Null Hypothesis (H₀): Represents the assumption that no significant difference or relationship exists between factors.
      • Often used as a starting point, assuming no effect is present.
    • Alternative Hypothesis (Hₐ): Represents the assumption that a significant difference or relationship does exist between factors.
    • In a comparison (e.g., method A vs method B), the null hypothesis suggests both are equally effective.
    • The alternative hypothesis posits that one method is more effective than another.
      • Symbolically, H₀: μ = μ₀, and Hₐ: μ ≠ μ₀, with μ being a population mean.

    Alternative Hypothesis Interpretations

    • Hₐ: μ ≠ μ₀: The population mean is not equal to the hypothesized mean.
    • Hₐ: μ > μ₀: The population mean is greater than the hypothesized mean.
    • Hₐ: μ < μ₀: The population mean is less than the hypothesized mean.

    Considerations for Choosing a Null Hypothesis

    • Risk avoidance: If rejecting a true null hypothesis carries high risk, it should be the null hypothesis.
    • Specific statements: The null hypothesis should make specific statements about a value, not general or close approximations.

    Significance Level

    • The significance level (often 5%, or 1%) is the risk a researcher is willing to take of incorrectly rejecting a null hypothesis when it's true.
    • It's the percentile for making decisions in hypothesis testing.

    Decision Rules and Hypothesis Tests

    • A decision rule, crucial for hypothesis testing, dictates when to accept or reject a null hypothesis.
    • Example: Given a lot of items, to accept Ho it must contain low number of defective items.

    Type 1 and Type 2 Errors

    • Type 1 error: Rejecting a true null hypothesis.
    • Type 2 error: Accepting a false null hypothesis.
    • Type 1 error (α) known as significance level.
    • Type 2 error (β) is less specific and hard to determine.

    Probability of Errors

    • Probability of type 1 error is typically set in advance.
    • It's a trade-off: reducing one error typically increases the other.

    Hypothesis Testing Steps

    • Formulating hypotheses: Define the null and alternative hypotheses.
    • Choosing the significance level: Set the acceptable risk of error.
    • Selecting a distribution: Choose the appropriate probability distribution.
    • Sampling randomly: Collect a sample and calculate necessary statistics.
    • Calculating probability: Compute the probability of obtaining the sample results if the null hypothesis is true.
    • Comparing probabilities: Compare the calculated probability to the significance level.
    • Final decision: Reject or accept the null hypothesis.
    • Test of Hypothesis Classification: Parametric versus Non-Parametric testing.

    Sources of Hypothesis

    • Culture: Traditions and contexts.
    • Scientific theories: Existing theory, usually affects culture.
    • Analogies: Other fields or ideas, providing possible theories.

    Parametric Tests

    • Based on assumptions about the distribution of the population.
      • These tests require a normal distribution.
    • Common examples include Z-test, T-test, Chi-square test, and F-test.

    Non-Parametric Tests

    • Often used when assumptions of normality cannot be made.
    • Common examples include sign test, Wilcoxon matched-pairs test, Wilcoxon-Mann-Whitney test, Kruskal-Wallis test, rank correlation, Kendall's coefficient of concordance, McNemar test.

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    Hypothesis Testing PDF

    Description

    Explore the critical concepts of hypothesis testing in research methodology. This quiz covers definitions, types of hypotheses, and their applications in decision-making processes. Improve your understanding of how hypotheses influence research outcomes.

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