Question 1

An investigator analyzes the results of an experiment and determines that p < .05.Why does the investigator want to know the value of p?

Accepted Answer

The value of p is used to determine whether the results of an experiment are statistically significant, meaning that the results are unlikely to have occurred by chance. A p-value of <.05 indicates that there is a less than 5% chance that the results occurred by chance, and therefore, the investigator can conclude that the results are statistically significant.

Question 2

The statement "p < .05" refers to

Accepted Answer

"p < .05" is a commonly used benchmark in statistical analysis that indicates the probability of getting a result by chance. Specifically, it means that there is less than a 5% chance that the observed difference between groups is due to random variation, and more likely reflects a true effect. This is typically considered a level of statistical significance necessary to support a hypothesis or observed effect.

Question 3

The mean,median,range,and standard deviation are all examples of

Accepted Answer

The mean, median, range and standard deviation are all measures of central tendency and variation that fall under descriptive statistics, which is concerned with summarizing and describing the characteristics of a dataset. Inferential statistics involves using sample data to make inferences or predictions about a larger population, while correlations involve examining the relationship between variables. Tests of significance are used to determine if the results of a study are statistically significant or just due to chance.

Question 4

An investigator decides to consider the results of an experiment to be statistically significant if p < .05.An analysis of the result indicates that p = .09.What conclusion,if any,can the investigator draw?

Accepted Answer

Since p = .09, which is greater than .05, the results are not statistically significant. Therefore, the investigator cannot draw any conclusion regarding the hypothesis being tested.

Question 5

Which of the following would (as a rule)indicate that a result is statistically significant?

Accepted Answer

A result is considered statistically significant if the p-value is less than 0.05 (p < 0.05). This means that there is less than a 5% chance that the observed result occurred due to chance alone, and suggests that there is a true effect or difference present in the data. The other options do not indicate statistical significance.

Question 6

If p < .05,then the difference in results between the experimental group and the control group is probably

Accepted Answer

If p < .05, it means that there is less than a 5% chance that the results observed could have occurred by chance alone. This indicates that the difference in results between the experimental group and the control group is statistically significant.

Question 7

If the standard deviation is small,then

Accepted Answer

If the standard deviation is small, it means that the data points are clustered closely around the mean. So, most scores are close to the mean.

Question 8

Mathematical summaries of results are called __________ statistics,while statistics that inform about the entire population,based on information collected from small samples,are called __________ statistics.

Accepted Answer

Descriptive statistics summarize data from a sample, such as mean or standard deviation, while inferential statistics use sample data to make generalizations about a larger population.

Question 9

In the statistical expression "p < .05," the "p" represents

Accepted Answer

In statistical analysis, "p" represents the probability of obtaining results as extreme or more extreme than the obtained results by chance. When a study finds a p-value less than .05, it means the probability of the results occurring by chance is less than 5%, which is considered statistically significant. Therefore, option D is the correct answer.

Question 10

A psychologist conducts an experiment and reports that p < .05.What is the relationship between the value of p and the statistical significance of the results?

Accepted Answer

A p-value of less than .05 indicates that there is less than a 5% probability that the results are due to chance. In other words, the results are significant and support the hypothesis being tested. Therefore, the lower the value of p, the more significant the results are.

Question 11

An investigator wishes to determine whether the difference between two groups of participants is statistically significant.To answer that question,the investigator must first determine the difference between the means of the two groups,the number of participants in each group,and

Accepted Answer

In order to determine whether the difference between two groups is statistically significant, the investigator must first calculate the difference in means and the sample sizes in each group. However, the amount of variation in each group is also critical to determining statistical significance. Therefore, C is the best choice as it identifies an important factor necessary for determining whether differences between groups are meaningful. A, B, and D are not directly relevant to determining statistical significance.

Question 12

Often we want to describe what the "average" person did.For this purpose the mean and median give similar results UNLESS

Accepted Answer

When a few individuals in the sample are extreme, unlike the others, the mean is affected more than the median. This is because the mean is influenced by outliers, while the median is not. Therefore, if we want to describe what the "average" person did in a sample with extreme individuals, it is better to use the median rather than the mean.

Question 13

A pre-school teacher records the height of all of her students and their parents.The distribution of these measures would be called a

Accepted Answer

A bimodal distribution is one where there are two distinct peaks or modes in the data. In this scenario, it would make sense for there to be two peaks - one for the heights of the preschoolers and one for the heights of their parents. A symmetrical distribution is one where the data is evenly distributed around a central value, which is unlikely in this case. A logarithmic distribution is one where the data is distributed in a logarithmic pattern, which is also unlikely in this scenario. A standard distribution is not a commonly used statistical term.

Question 14

Which of the following is used in calculating a standard deviation?

Accepted Answer

Standard deviation is calculated based on the average or mean of the data set. The range, mode, and median are not used in calculating the standard deviation.

Question 15

The standard deviation is a statistic that measures

Accepted Answer

The standard deviation measures the amount of variation in a set of data. It tells us how spread out the data is from the average or mean value. It is a useful tool for understanding the distribution of data and for making comparisons between different sets of data.

Question 16

If most scores are very close to the mean,then the standard deviation is

Accepted Answer

If most scores are very close to the mean, it means there is little variation in the data set, and as a result, the standard deviation would be very small.

Question 17

Which of the following is an example of an inferential statistic?

Accepted Answer

An inferential statistic is used to make inferences about a population based on a sample. The p-value from a statistical test is an example of an inferential statistic because it allows us to draw conclusions about a population based on the results of a sample. The mean, median, and standard deviation are descriptive statistics, which summarize information about a sample or population but do not make inferences about a larger group.

Question 18

A survey asked how many sex partners you hope to have in the future.The majority of men answered 1,2,or 3,yet the mean was 64.How can that be?

Accepted Answer

The majority of men answered 1, 2, or 3, which are relatively low numbers. However, there could be a few participants who reported extremely high numbers, which would greatly influence the mean and pull it up to 64. Thus, extreme scores can have a significant impact on the mean, even if they are not representative of the majority of responses.

Question 19

What does it mean to say that "p < .05"?

Accepted Answer

Saying that "p < .05" means that the probability of getting the observed pattern of results by chance is less than 5%. This is known as the significance level or alpha level, and it is a common way of determining whether a result is statistically significant (i.e., unlikely to have occurred by chance). A p-value of less than .05 is generally considered significant in most fields of research.

Question 20

A particular research study compares an experimental group with a control group.An analysis of the results reveals that "p < .05." Therefore,

Accepted Answer

A p-value of less than .05 means that there is a less than 5% chance of getting the observed difference by accident. This indicates that the results are statistically significant, and that there is a significant difference between the experimental group and the control group.

Quiz 2: Scientific Methods in Psychology