Week 10 Flashcards
What do researchers must ensure?
Ensure that interviews were administered properly and completely
What is editing?
Involves checking for interviewer and respondent mistakes
What is a skip pattern
Sequence which later questions are asked, based on the respondents answer to earlier question or questions
What are the editing process for paper surveys
- Whether the interviewer fails to ask certain questions or record answers for certain questions
- Whether skip patterns are followed
- Whether the interviewer paraphrased respondents answers to open ended questions
What is coding
Refers to the process of grouping and assigning numeric codes to responses to a particular questions
What should closed ended questions be
Precoded
What do open ended question do
Create coding dilemma snd were phrased this way because the researcher had no idea what answers to expect or wanted a richer response
What is the coding process
- List responses: Prepare lists of actual responses given to each open ended question on a survey
- Consolidate responses
- Set codes: A numeric code is assigned to each of the categories on the final consolidated list of responses
- Enter codes:
- Review responses to individual open ended questions on questionnaires
- Match individual responses with the consolidated list of response categories and determine the appropriate numeric codes
- Write the numeric code in the appropriate place on the questionnaire of the response or enter code in the data base electronically
What is data entry
- The process of converting information to a form that can be read by a computer
- This requires data entry device
What is intelligent data entry
The information entered is checked for internal logic and can be programmed to avoid certain types ferrous at the point of data entry
What is the data entry process
Validated, edited and coded questionnaires given to a data entry operator seated in front of a personal computer
What is the scanning technology
Form of data entry which responses on questionnaires are read in automatically by data entry device
What is logical or machine cleaning of data
Final computerized error check of data
What is error checking routines
Makes sure that the data are logically consistent
What are one way frequency tables
Shows the number of respondents who gave each possible answer to each question
What are the three components of the one way frequency table
- Total respondents
- Number of people asked the particular question
- Number of people answering the question
What are cross tabulations
- Examination of the responses to one question relative to the responses to one or more other questions
- Looks at the responses to one question in relation to the responses to one or more other questions
What do the cross tabulations include
Frequencies and percentages with the percentages based on column totals
What are common ways of setting u cross tabulation tables
Use columns to represent factors such as demographics and lifestyle characteristics which are expected to be predictors of the state of mind, behaviour, or intentions data shown as rows of the table
What are line charts
Simplest forms of graphs usually to measure overtime
What are pie charts
Displays marketing research results in a wide range of situations
What are 4 types of bar charts
- Plain bar chart (simple)
- Clustered baar chart: shows cross tabulations
- Stacked bar chart (represents cross tabulation results)
- Multiple-row, three dimensional bar chart this is the most visually appealing way to present cross tabulation information
What are descriptive statistics
Efficient means of summarizing the basic characteristics of large sets of data
What are three measures of central tendency
Arithmetic mean, median, mode
What is mean
Average
What is median
Value below which 50% of the observations fall
What is mode
Value that occurs most frequently and can be computed for any type of data
What are the use of statistical tests
Indicates whether two means have a significant relationship between two variables in a cross tabulation table
What is statistical significance?
Difference that is large enough that is not likely to have occurred because of the chance or sampling error
What are three things to keep in ind for testing statistical difference
- Random samples are assumed
- Big data does not mean good data
- Don’t overly on significance testing
What is hypothesis
Theory that the researcher makes about the characteristic of the population being investigated
What are the steps of hypothesis testing
- State the hypothesis
- Choose the appropriate statistical test
- Developing a decision rule
- Calculating the value test statistic
- Stating the conclusion
What is null hypothesis
Hypothesis that is tested against the complement to research hypothesis of interest
What is a decision rule
A decision rule is needed to determine whether to reject or fail to reject the null `
What is the significance level
Critical in the process of choosing between the null and alternative hypothesis
How do you calculate the value
- Use the appropriate formula to calculate the value of the statistic for the test chosen
- Compare the value just calculated to the critical value of the statistic based on decision rule chosen
- Based on the comparison, determines to either reject or fail to eject the null hypothesis
What is type I error
- Involves rejecting the null hypothesis when it is in fact
- This is alpha level
What is type II error
- Involves failing to reject the null hypothesis when is actually false
- This is referred beta error
What is the level of alpha set by the researcher
Considering the resources available for the project, and considering the implications of making type I and type II errors.
What happens when you accept H0 vs failing to reject H0
- H0 is presumed to be true until its demonstrated as likely to be false
- We have to prove H2 in order to accept
What are tests either one tailed or two tailed
- A one-tailed testresults from an alternative hypothesis which specifies a direction
- A two-tailed test will test both if the mean is significantly greater than x and if the mean significantly less than x.
What are independent samples
Those in which the variable of interest in one sample has no effect on measurement of the other sample
What are related samples
Measurement of the variable of interest in one sample may influence measurement of the variable in another sample
What are degrees of freedom
The number of observations in a statistical problem that are not restricted or are free to vary
What are the equations to the degrees of freedom
Equal to the number of observations minus the number of assumptions or constraints necessary to calculate the statistic
What are Chi-Square Tests
Tests of the goodness of fit between the observed distribution and the expected distribution of a variable
How do you do the chi-square tests single independent samples
- Specify the null and alternative hypothesis
- Determine the number of visitors who would be expected in each category if the null hypothesis were correct
- Calculate the x^2 value
- Select the level of significance
- State the result
How do you do chi square tests of two independent samples
- State the null and alternative hypothesis
- Place the observed (sample) frequencies in a cross tabulation or contingency table forand calculate each row and each column, record those totals at the margins of the table and calculate the total for the entire table
- Determine the expected frequency for each cell in the contingency table and calculate the product of two marginal totals common
- Calculate the value of x^2
- State the result
What is population
It is from the population that we derive our sample
What is a sample
Representative of chunk of the population who form the respondents/participants who are a part of your research
How do you select the sample
By including people who are a part of the population
What do you need to avoid in a sample
Including people who are not a part of the population
What is the results of sample when its done properly
The results from the sample should be reflective of the population
What is probability
Probability samples are selected in a way that every member of the population has known, non-zero likelihood of selection
What is non probability
Does not meet probability sample standard
Why probability sampling
Probability sampling allows for the calculation of the extend to which a sample value can be expected to differ from a population value
What is simple random sampling
Having all the population element have the same probability of being included
What is systematic sampling
This can be substituted for random sampling and uses skip interval to pick elements from population
What is stratified sampling
Divide parent population into mutually exclusive groups and forces all elements of the population to be represented
How do you determine strata
Usually demographic characteristic/behaviour
What is stratified sampling
Researchers divide subjects into subgroups called strata based on characteristics that they share
What are 3 ways for cluster sampling
- Divide population into mutually exclusive and exhaustive sets
- Random sample of subsets selected
- Members selected: All members of selected subsets and members selected probabilistically from subsets
What are the benefits of a large sample size
Reduces random error
What are the disadvantages of having a large sample size
Its costly
What are non probability sampling types
- Convenience sampling
- Judgement samples
- Quota samples
- Snowball samples
What is convenience sampling
Based on convenience
What is judgement sampling
Based on researchers judgement of what constitutes a representative sample
What is quota sampling
Defines quotas in the population
What is snowball sampling
Additional respondents selected based on referrals
