I have one more file that needs to be edited too but I could not upload another document. Basically, each assignment has been submitted once but the professor has indicated the errors and points deducted. I only need those specific answers completed to resubmit the document by 5/5.
Running head: CHAPTER 1 COMPREHENSION QUESTIONS Chapter 1 Comprehension Questions Gwynnedolynne James Liberty University 1 Robin Henson @ 2019-03-25T18:32:15-07:00 no need for a cover sheet CHAPTER 1 COMPREHENSION QUESTIONS 1 1) Chapter 1 distinguished between two different kinds of samples: a. random samples (selected randomly from a clearly defined population) b. Accidental or convenience samples 1.1 Which type of sample (a or b) is more commonly reported in journal articles? The type of sample that is more commonly reported in journal articles truly depends on the specific type of journal. When the journal is based on laboratory studies in the field of psychology then accidental/convenience samples are more commonly used. However, some reports from national surveys are more based on randomized sampling. 1.2 Which type of sample (a or b) is more likely to be representative of a clearly defined population? (A), random sampling is the type of sampling that more likely represents a clearly defined population. 1.3 What does it mean to say that a sample is “representative” of a population? A sample is “representative” if the structure or make up of the sample is similar to the structure or make up of the population. An example would be surveys surrounding voting targets. A survey to project the outcome of an election or voting poll should be based on a sample that has a “representative” structure or make up in terms of the various political affiliations. 2) Suppose that a researcher tests the safety and effectiveness of a new drug on a convenience sample of male medical students between the ages of 24 and 30. If the drug appears to be effective and safe for this convenience sample, can the researcher safely conclude that the drug would be safe for women, children, and persons older than 70 years of age? Give reasons for your answer. If the samples from the population given above is the only samples used, the answer would be no because it would be too risky to make a conclusion that the researcher gathered enough data to make a conclusive evaluation that the drug would be safe for men, women, children, elderly, adolescents, etc. The sample appears to be too narrow and excludes many other needed populations and samples required to make such a conclusion. 7) Look at the standard normal distribution in Figure 1.4 to answer the following questions: a. Approximately what proportion (or percentage) of scores in a normal distribution lie within a range from -2? below the mean to +1? above the mean? .1359 + .3413 + .3413 = .8183 or about 81.83% b. Approximately what percentage of scores lie above +3?? .0013 or about .13% c. What percentage of scores lie inside the range -2? below the mean to +2? above the mean? What percentage of scores lie outside this range? 2 Robin Henson @ 2019-03-25T18:33:55-07:00 fair enough, but most are convenience samples in counseling/psych/education. CHAPTER 1 COMPREHENSION QUESTIONS 2 The percentage is approximately 95.44% of scores lie within the range from -2s below the mean to +2s above the mean; approximately (100 – 95.44) = 4.56% of the scores lie outside this range. 8) For what type of data would you use nonparametric versus parametric statistics? Nonparametric statistics is most commonly used when the following characteristics are present: Scores on the dependent variable are nominal or ordinal Scores on quantitative variables are not normally distributed The number (N) of participants within each group is small. The variances of scores are not equal across groups. Parametric statistics is more widely and more commonly used. Tests such as the independent samples t test, Pearson r, and ANOVA generally require that the following characteristics are present: Scores on the dependent variable are interval-level ratio of measurement. Scores on quantitative variables should be circa normally distributed. The number (N) of participants within each group should be equitably large. Variances of scores should be as close to equal across groups. Warner (2012) notes that although many researchers prefer to use parametric statistics in their practice, they do make exceptions when the assumptions are severely violated. 9) What features of an experiment help us to meet the conditions for casual inference? The features of an experiment that help us to meet the conditions for inference are as follows: Temporal Precedence of X relative to Y. This is the manipulation by the researcher of the X “casual” variable which is followed by the measurement or observation if the Y outcome variable. Covariation of X and Y: This is the researchers use of statistics to determine whether scores on X and Y tend to go together. Rule out all confounds or rival explanations: experiments are conducted and researchers arrange the research situation so that the other variables maintain their constant state and if not held constant, at a minimum, maintained the same across groups. When all of these conditions are met, it is still not possible for researchers to interpret the outcome of a single study as “proof” of causation. The final outcomes of any single study may be influenced by many other varying errors. 10) Briefly, what is the difference between internal and external validity? Warner (2012) sums internal validity up as the degree to which the outcomes from a single or multi-part study are used to determine the connection between the variables. This study is usually a well-controlled experiment that offers better supporting evidence for casual inference than nonexperimental studies. The text also summarizes external validity as the level to which a study outcome is generalized to participants, settings, and materials outside those actually included in the research. 3 4 5 Robin Henson @ 2019-03-25T18:36:03-07:00 no need to cite for these. I know the source is your text. Robin Henson @ 2019-03-25T18:37:31-07:00 these are conditions for causal inference, not features of the experimental design. this 3rd point is closest, but what features allow you to control for variables? what features allow support for internal validity? Robin Henson @ 2019-03-25T18:40:49-07:00 great. now think about what features of a well controlled experiment will help answer the question above. CHAPTER 1 COMPREHENSION QUESTIONS 3 12) Give an example of a specific sampling strategy that would yield a random sample of 100 students taken from the incoming freshman class of a state university. You may assume that you have the names of all 1,000 incoming freshmen on a spreadsheet. Use a spreadsheet listing 1,000 random numbers placed into Excel. The column with the 1000 random numbers should be next to a column of the 1000 students’ names (based on the assumption that all student names are known). To randomize the sampling, the researcher can select one digit at random such as number 7 and contact all students whose name is next to the randomly selected number that ends in “7”. 14) Is each of the following variables categorical or quantitative? (note that some variables could be treated as wither categorical or quantitative). Number of children in a family – This is classified as quantitative variable, however could be treated as categorical variable. Type of pet owned: 1=none, 2=dog, 3=cat, 4= other animal – This is classified as categorical variable. IQ score – This is classified as quantitative variable. Personality type (Type A, coronary prone; Type B, not coronary prone). – This is classified as a categorical variable. 15) Do most researchers still insist on at least interval level of measurement as a condition for the use of parametric statistics? No, most researchers do not. Statisticians have argued for “less strict application” (Warner, 2013, p. 7). Researchers/ statisticians have applied tests such as the t test, Pearson r, and ANOVA to scores that are obtained by using 5 and 7 point scales of ratings. The practice is considered acceptable in the scientific field but there is a large population of researchers that conform to more strict levels of statistical measurements. 17) Howdo between-S versus within-S designs differ? Make up a list of names for imaginary participants and use these names to show an example of between-S groups and within-S groups. Between -S: known as an Independent Sample Design. The design is when participants are assigned to or observed in only one group, with no exceptions. In other words, each category has unique/different participants with no one participant repeating the study. Study/Test/Observation 1 Study/Test/Observation 2 Study/Test/Observation 3 Sonia William Bryan Cynthia Dolores Bella Patrick Monica Shelby Atavius Michelle Crystal Debra Clifton Isaac Jessica Gary Christy 6 7 Robin Henson @ 2019-03-25T18:41:39-07:00 how? It's a frequency count, such that 4 kids is twice as many as 2 kids. Robin Henson @ 2019-03-25T18:42:22-07:00 try to avoid quotes for these assignments and just paraphrase into your own words CHAPTER 1 COMPREHENSION QUESTIONS 4 Within -S: also known as Repeated Measures Design. The design is when participants partake in a study, test or observation at various times or are given different treatments. The same participant can be used in all different studies as seen in the diagram below: Study/Test/Observation 1 Study/Test/Observation 2 Study/Test/Observation 3 Jermaine Jermaine Jermaine Nevaeh Nevaeh Nevaeh Brenda Brenda Brenda Donniece Donniece Donniece Kennedy Kennedy Kennedy Sid Sid Sid Reference Warner, R. M., Applied Statistics (2012). Thousand Oaks, CA. Sage Publications Group Comment Summary Page 1 1. no need for a cover sheet Page 2 2. fair enough, but most are convenience samples in counseling/psych/education. Page 3 3. no need to cite for these. I know the source is your text. 4. these are conditions for causal inference, not features of the experimental design. this 3rd point is closest, but what features allow you to control for variables? what features allow support for internal validity? 5. great. now think about what features of a well controlled experiment will help answer the question above. Page 4 6. how? It's a frequency count, such that 4 kids is twice as many as 2 kids. 7. try to avoid quotes for these assignments and just paraphrase into your own words Running head: CHAPTER 2 COMPREHENSION QUESTIONS Chapter 2 Comprehension Questions Gwynnedolynne