use of inferential stats

• why do we use inferential statistics?

  To see what type of hypothesis is most appropriate (alternative or null).
• Which hypothesis do we accept when there is a significant difference?

  The alternative hypothesis (H1).
• Which hypothesis do we accept when there is not a significant difference?

  The null hypothesis (H0).
• what percentage of certainty is needed to say the IV changed the DV?

  95%
• probability

  The likelihood that results are caused by chance.
• what level of probability is used by psychologists unless stated otherwise?

  P = 0.05
• why are different levels of probability sometimes used?

  Different probability levels are used if studies might affect human life e.g., new drug trial.

  In these cases, psychologists will use a level like P = 0.01