1. You just collected the compliance values from some patients: 0.8, 1.0, 1.1, 1.4, 4, 0.9, 0.4, 0.5, 1.1, 1.2
  • What is the mean
    • the sum of all quantities divided by the number of quantities; an average
      • sum = 12.4
      • number of quantities = 10
      • 12.4/10 = 1.24 or 1.2
  • What is the median
    • the midpoint of a distribution of a set
    • 10 numbers, no true mid number, take two mid numbers and find their midpoint
    • 1.05
  • What is the mode
    • the value that occurs most frequently in a set
    • 1.1
  • What is the standard deviation
    • extent of deviation for a group as a whole
    • add up the value of all numbers in a set
    • divide by amount of numbers in set
    • square root
    • 9.32/10 = 9.32 sqrt9.32 = 0.965
  • What are the variance values of this data set?
    • population standard variance is the standard deviation value squared
    • 0.965^2 = 0.9304
  • *What is the sample standard deviation?
    • 1.016
  • *What is the sample standard deviation variance?
    • 1.016^2 =
    • 1.033
2. You have been fitting pediatric patients successfully with hearing aids. Now you want to compile the fitting data (brand, model, gains, fitting formulas, age, gender, etc.) for a research project. Do you need to apply for an IRB review? Why or why not?
  • IRB Review
    • Under FDA regulations, an IRB is an appropriately constituted group that has been formally designated to review and monitor biomedical research involving human subjects. In accordance with FDA regulations, an IRB has the authority to approve, require modifications in (to secure approval), or disapprove research.
    • Any activity that is a clinical investigation or involves medical intervention or procedures, even when they are a part of a course curriculum, always constitutes human subjects research and requires prior IRB review and approval.
    • IRB approval is necessary for human subject research which will result in publication in a graduate or senior student essay or thesis. ... In most cases, class projects involving human subjects are not intended to contribute to generalizable knowledge and therefore are not covered under the federal regulations for IRBs.
    • This policy details the roles and responsibilities of IRB and the OIRB. The IRB/Institutional Review Board (IRB) is a committee established to protect the rights and welfare of human research subjects involved in research activities as prescribed by federal regulations.
3. If you were to examine the difference of wave V latencies of click-ABR at 80 dB HL in younger adults and older adults, assuming all extraneous variables are well controlled and equal variances between the two groups, which research design would be your first choice? What are the IVs, DVs and possible EV in this study? What types of data are these variables (scales of measurements)? Which statistic test(s) would you use?
  • Research Design
    • Between Group Design
  • Independent Variable/IV
    • Age
  • Dependent Variable
    • Latencies
  • Extraneous Variables/EV
    • Pathology
  • Scales
    • Ratio
  • Statistic Test
    • T Test
    • Determines if there is a statistically significant difference between the two age groups.
4. If you were to examine the differences of wave V latencies of click-ABR at 40, 60 and 80 dB HL, in younger/older male/female adults, assuming all extraneous variables are well controlled, which research design would be your first choice? what are the IVs, DVs and possible EVs in this study? What types of data are these variables (scales of measurements)? Which statistic tests would you use?
  • Research Design
    • Mixed Design
      • (between = age/gender)
      • (within = dB HL)
    • Independent Variable
      • dB HL
      • Age
      • Gender
    • Dependent Variable
      • Latencies
    • Extraneous Variables
      • Pathology
    • Scale
      • Ratio
    • Statistic Test
      • T Test
        • To determine if there is a statistically significant difference between the groups
5. Often times, you will read things like "...result from group A is significantly greater than that of group B (p < 0.05)". What is this p value? How do you use the p value to evaluate your null hypothesis?

  • The p-value is the level of marginal significance within a statistical hypothesis test representing the probability of the occurrence of a given event. If the p value is less than the set p value, it means the result did not occur by chance and the null hypothesis can be rejected
6. WHEN and HOW do we use z-test, one sample t-test, pairwise dependent t-test and two samples independent t-test? WHEN do we use correlation, regression, Chi-square, one way ANOVA and Repeated measures of ANOVA?

  • z-test - when we have a standard deviation of population and we want to compare one data point to the population data
  • t-test - statistically significant difference between two independent sample groups
  • pairwise dependent  t-test - statistical procedure used to determine whether the mean difference between two sets of observations is zero
  • two samples independent t-test - compares the means of two independent groups in order to determine whether there is statistical evidence that the associated population means are significantly different
  • correlation - relationship between variables
  • regression - prediciting
  • chi-square test - a statistical test often used for analyzing categorical data
    • O: observed frequency in each category
    • E: expected frequency in each category
7. Assume the population mean (u) of normal hearing adults hearing sensitivity at 1000Hz is 20 dB HL, with a standard deviation of 4 dB (standard deviation) and a patient's tested threshold is 22 dB HL, is the patient's hearing at 1000Hz within normal range? (All EVs well controlled, using p < 0.05)
  • Yes. Z score of 0.5 which is within normal range
8. Read the attached article on infant's pitch perception. Focus on the introduction part. What is the research question? What is the purpose of the study? Why is it important to examine it?
9. Design a study to examine the difference between/among adult normal hearing, hearing impaired with hearing aids and CI recipients scores in ASBio sentence list test (You don't have to be an expert on this specific test. Each test will have a score, just like any other behavioral speech perception test.).
  • Independent variable
    • hearing status
  • Dependent variable
    • AZBio test scores
  • Between Design
    • Between = Group (3)
  • Descriptive
    • Simple observation of test result