LECTURE 4_Significance Tests Flashcards
An important quality of an analytical method
free from bias
Why are significance tests conducted?
Significance tests are widely used in the evaluation of experimental results
It is used to o decide whether the difference between the measured and standard amounts can be accounted for by random errors,
What are the steps in significance testing?
- State the null hypothesis
- State the alternative hypothesis
- Check the distribution of data
- Select the appropriate test
- Choose the level of significance for the test
- Choose the number of tails for the test
- Calculate the test statistics
What is the use of t-test?
We use a t-test to compare one mean value with another to decide whether there is a statistically significant difference between the two.
What does the null hypothesis state?
null hypothesis in statistics states that the mean values from two sets of measurements are not different
What is a one sided test?
Has only 1 critical region.
For only 1 type of outcome
What is a two-sided test?
testing for a difference between two means in either direction.
What is a significance level?
It is the probability that the event could have occurred by chance.
What is a critical value?
It is a number that separates the acceptance and rejection regions of a hypothesis test. It’s used to determine if a result is statistically significant.
What is an outlier?
These are values that differ from most other data points in a dataset.
What is ANOVA?
Analysis of variance (frequently abbreviated to ANOVA) is an extremely powerful statistical technique which can be used to separate and estimate the different causes of variation
It can be used to separate any variation which is caused by changing the controlled factor from the variation due to random error. It can thus test whether altering the controlled factor leads to a significant difference between the mean values obtained
What does ANOVA test? How does it differ from t-test?
ANOVA tests whether there are statistically significant differences between THREE OR MORE samples.
t-test is only limited to 2 samples.
What is Chi-squared test?
A chi-square test is a statistical test used to compare observed results with expected results. The purpose of this test is to determine if a difference between observed data and expected data is due to chance, or if it is due to a relationship between the variables you are studying.
