Reporting results and drawing conclusions

On watching this video students should be able to:

1. Explain that when drawing conclusions from inferential results we often have to exercise good judgement on aspects other than the solitary confidence interval or p-value that we are interpreting; for example, have multiple tests been performed? is the study powerful enough? Is this effect of any practical significance?
2. Discuss the aphorism “absence of evidence does not mean evidence of absence” and apply it to exercise good judgement when interpreting larger p-values and wide confidence intervals that contain the null value.
3. Justify why two-tailed p-values are generally preferred over one tailed p-values.
4. Define a type 1 and type 2 error.
5. Explain why a post hoc test can only be interpreted as hypothesis generating and why it is not valid to trawl the data for patterns and then perform hypothesis tests on the patterns you see.