L5

Question 1

what is sampling?

Answer 1

A sample is a small part of the population, and the point of sampling is to infer from the characteristics of the sample onto the population

Question 2

What are sampling errors?

Answer 2

these are the differences between the sample statistics and population parameter. Sampling error is always present when making statements about a population

Question 3

What is the main strategy to reduce sampling error?

Answer 3

Increase the sampling size, as the larger the sample, the lower the error

Question 4

What is sampling bias and what are the 3 types?

Answer 4

The systematic tendency to sampling error
1. Self-selection bias - participants with specific characteristics are more likely to take part in a study than others
2. Pre-screening - the way participants are pre-screened may lead to a sample bias
3. Under-coverage - specific members of the population are inadequately represented in the sample

Question 5

What is sampling bias a threat to?

Answer 5

It is a threat to external validity, as it limits the generalizability of research findings to the broader population

Question 6

What are the main sampling techniques?

Answer 6

Probability and non-probability sampling

Question 7

so what is probability sampling and what are the methods?

Answer 7

Probability samples reduce the risk of sampling bias and enhance internal/external validity
1. Random sample where people are randomly picked
2. Stratified sample where individuals are grouped based on distinguishing factors, then random sampling is done in each one

Question 8

what is non-probability samples?

Answer 8

anyone who passes by can be selected.

Question 9

Null vs alternative hypothesis?

Answer 9

The null hypothesis (H0) is the default hypothesis that a quantity (e.g coefficient, difference) is equal to 0
The alternative hypothesis (H1) states the quantity is different than 0

Question 10

please look at the document for methods in decision criteria for rejeccting the null

Question 11

What are univariate tests?

Answer 11

tests to examine whether the sample is representative of the population of a sample.

Question 12

when is a one-sample t-test used?

Answer 12

This is used to determine whether the mean of a quantitative variable is equal to an expected value
The variable is quantitative. So average age in sample = 22

Question 13

when is a one-sample chi square used?

Answer 13

this is used to determine whether the distribution of a categorical variable is equal to an expected distribution.
H0: distribution of nationality = distribution in population

Question 14

look at how results are written!!

Question 15

ways to design a good survey

Answer 15

1. good introduction and closing and not being too specific about the topic
2. get peoples’ interest
3. be specific
4. be mindful about ordering the questions