Statistical Methods for Psychology

our hypothetical distribution of differences when the null hypothesis is false, and the alter- native hypothesis ( ) is true. Re ...

important to avoid Type I errors (such as falsely claiming that the average driver is rude), then you would set a stringent (i.e ...

is actually true, that is, a5.10. We are rarely willing to work with aas high as .10 and prefer to see it set no higher than .05 ...

mind that with respect to a given tail of a distribution, the difference between a one-tailed test and a two-tailed test is that ...

of .045 that we have here is the probability of the data given that H 0 is true [written p(D|H 0 )]— the vertical line is read “ ...

they will certainly differ by at leastsome trivial amount.^4 So we know before we begin that the null hypothesis is false, and w ...

not rejecting the null because saying that we don’t have enough evidence is not the same as incorrectly rejecting a hypothesis. ...

deviation. Expressing the difference between waiting times in terms of the actual number of seconds or as being “nearly half a s ...

Before we can apply our statistical procedures to the data at hand, we must make one additional decision. We have to decide on a ...

Exercises 107 Exercises 4.1 Suppose I told you that last night’s NHL hockey game resulted in a score of 26–13. You would probabl ...

108 Chapter 4 Sampling Distributions and Hypothesis Testing 4.12 Describe a situation in daily life in which we routinely test h ...

Exercises 109 4.27 There has been a suggestion in the literature that women are more likely to seek help for de- pression than m ...

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CHAPTER 5 Basic Concepts of Probability CHAPTER 5 Basic Concepts of Probability Objectives To develop the concept of probability ...

IN CHAPTER3 we began to make use of the concept of probability. For example, we saw that about 19% of children have Behavior Pro ...

that is not a requirement. What is the probability that you will pull out a blue M&M? You can all probably answer this quest ...

of the Colorado Rockies winning the pennant is high, we are stating our subjective belief in the likelihood of that event (or pe ...

p(blue) 5 24/100 5 .24, p(green) 5 16/100 5 .16, and so on. But what is the probability that I will draw a blue or green M&M ...

messages were found in the trash, which is a bit higher than we would expect if the ultimate disposal of the fliers were indepen ...

as is the probability that a flier would both contain a message about littering and be found stuffed down behind the Raisin Bran ...