Chapter 8 Flashcards
What is a hypothesis?
Tentative statement about relationship between two or more variable
What is hypothesis testing?
tests whether hypothesis provides plausible explanation for experimental findings
What is proof of contradiction?
Proposing null hypothesis and then providing evidence that supports the rejection of the null hypothesis to support Ha
What is the concept of rationale (longer explanation okay if you don’t memorize but know it)
It is impossible to say with complete certainty that an effect in a experimental condition is due to a particular cause, never possible to rule out or control for extraneous variable
What is the closest a researcher can come to proving an effect?
Claim outcome is reliable with a small margin of error
What is step one in setting up hypothesis testing?
Research hypothesis
What is step two in setting up hypothesis testing?
Null hypothesis and alternative are stated
What is step 3 in sett ing up ht?
Descriptions of variables being tested
What is step four in setting up ht?
Description of pop of interest and how it is represented in experiment
What is step 5 in setting up ht?
Identification of experimental group and control
What is step 6 in setting up ht?
Statement definition of how results are to be measured
The core logic of hypothesis testing is built around the concept of
Proof by contradiction
The null hypothesis is stated so as to be _________ to the alternative hypothesis.
complementary
What is the scientific method?
Model for conducting research
What are the steps for the scientific method?
Question, research, hypothesis, test hypothesis, analyze and draw conclusions, communicate results
Constructing a testable hypothesis is one step in the ______ _______
Scientific method
What are competing hypotheses?
different potential explanations for phenomenon tested against each other
What are the two competing hypotheses?
Null and Alternative
What is the null hypothesis?
Statement about a population parameter assumed to be true unless there is convincing evidence to the contrary
What is the core logic of hypothesis testing?
Null
What does the null hypothesis state?
Expected difference btw groups being compared is not there
What is the alternative hypothesis ?
directly contradictory to null
What does the alternative summarize?
expected or predicted outcome of investigation at hand
What is the alternative also called?
Research hypothesis
What happens if the null and alternative are compared together?
They represent mutually exclusive outcomes
What is actually being tested in an experiment?
The null
The purpose of hypothesis testing is to establish the truth of the research hypothesis. (t/F)
False
What are the 3 elements of a testable hypothesis?
Identifies groups being compared, specifies level of measurement to be used, states direction of effect in terms of DV
What is the alternative hypothesis (in terms of stating)?
Completely stated, measurable outcomes spells out precisely what differences are to be expected and found between groups
Why is directionality important?
Determines whether tests of significance is one or two tailed
What does a directional hypothesis state?
One measure will be more or less than comparison measure (direction of expected diff.)
What does a non-directional hypothesis state?
two measure will be diff from each other, not a direction
What are the majority of real-world hypotheses?
Non-directional
What is an experimental study?
Introduction or manipulation of IV, while measures on DV are observed (active manipulation. of IV)
Should the hypothesis be broad or specific?
Specific to get best results (what is expected result, what is manipulated, what expected change is, how it is to be measured)
What is a non-experimental study?
Pre-existing differences not controlled differences
How is the alternative usually stated?
Action statement and a complete sentence
What is the difference between an experimental and non-experimental study?
In an experimental study the IV is actively manipulated while in a non-experimental study the IV is not actively manipulated.
Can you put no difference as the null for directional?
No, you should predict direction
Is it null or not? Statement chart
Alternative:
not equal to k: Ha: u ‡ k
… less than k: Ha: u< k
greater than k: Ha:u> k
Null:
equal to k: Ho: u = k
greater than or equal to k: Ho: u≥ k
less than or equal to k: Ho: u <- k
Does the null ever have <>
No, always have to have the line underneath
Given the statement, H1: µ1 > µ2, what is the correct null hypothesis?
H0: µ1 ≤ µ2
Given a research hypothesis that the average test score of students in online class sections will be different from the average test score of students in classroom-based sections, identify the correct null hypothesis:
H0: µ1 = µ2
The null hypothesis is considered as the ______ outcome.
No effect
What is the comparison distribution?
Results of the study are compared, represents when the null is true, baseline
What does the comparison distribution allow?
determine reliability from a single measure or change as a result of experimental treatment
What is the function of the comparison distribution?
It provides the statistical distribution to which the results of a study are to be compared.
The appropriate comparison distribution for comparing an individual score to a known population parameter is a distribution of sample means. (t/f)
False
The appropriate comparison distribution to use when comparing a sample mean to a known population mean is a distribution of ______.
means
What is the cutoff score?
critical value that marks certain areas of comparison distribution to reference for tests of significance
what is the significance level represented by?
Alpha (.05 or .01)
If it is a two tailed test what do you do to alpha?
divide it in half
What happens with an alpha score of .05?
cuts off the most extreme 5% of the distribution. A score that falls into that area is likely to occur less than 5% of the time if the null hypothesis is true, provides support to alternative hypothesis
What is a one-tailed test?
Test that predicts more than or less than, because the outcome is in a specific direction
What leads to a right tail test?
Higher score or more than
What leads to a left tail test?
Lower score or less than
What is a two tailed test?
Predicts a different from outcome and does not specify direction
What determines alpha?
Size of the rejection region
A research hypothesis that makes a prediction of a lower score on a measure of the DV would require a ________.
Left test
A two-tailed test is appropriate for a hypothesis that does not predict a —- outcome.
more than or less than
What is the rejection region?
Area that lies beyond the cutoff score
What is the critical value approach?
Test statistic that exceeds predetermined critical value provides evidence
What is the p-value approach?
Probability of obtaining a result at least as extreme as one observed if null is true
What is a larger sample more likely to provide?
Statistically significant outcomes
With a two-tailed test, the rejection region is __________.
Split between the two tails of the distribution
The p-value of an outcome is the probability of obtaining this result given that the null hypothesis is _________.
true
Along with whether a result has statistical significance, a researcher should also be concerned with whether the result has ____ significance.
practical
Step 1 in hypothesis testing
State claim and identify null and alternative
Step 2 in hypothesis testing
Determine alpha
Step 3 in ht?
Determine appropriate test to use
Step 4 in hypothesis testing?
Identify critical value
Step 5 in ht?
Calculate test statistic
Step 6 in ht?
decide to fail or reject H0
Step 7 in ht?
Interpret decision
What are inferential statistics?
allow you to make inferences based on a data set
What can we test with hypotheses?
if one sample belongs to known pop, if two sample came from same or diff pop, if more than two samples come from same pop
When should hypotheses be stated?
Before data is collected in terms of uhyp
