Sampling Bias #1 by Helen Hailin Zhao

Question: if researchers would like to conduct surveys to understand the shopping behaviors of the public and they chose to send out surveys at a shopping mall. What are the biases here?

hhzhao — 2024-09-11 23:57:53 UTC

hhzhao — 2024-09-11 23:58:22 UTC

3036341383 — 2024-09-13 11:06:17 UTC

Ignore the people who buy things online

3036343226 — 2024-09-13 11:06:35 UTC

A single shopping mall might not be the best representation of consumer shopping behaviours in general.

3036348197 — 2024-09-13 11:06:47 UTC

those who perfer shopping online are not involved in the sample

3036341450 — 2024-09-13 11:07:08 UTC

Only capturing the behaviors of shoppers who visit the mall, and may exclude non-shoppers or those who shop elsewhere.

3036342337 — 2024-09-13 11:07:12 UTC

They only conducted a survey on those who appear at the shopping mall, but these people cannot stand for the public.

3036348109 — 2024-09-13 11:07:17 UTC

the sample covers only those who have the hobbit of shopping

3036341979 — 2024-09-13 11:07:21 UTC

They cannot acquire the shopping habits of people who do not like to go to shopping mal to purchase goods.

3035638973 — 2024-09-13 11:07:24 UTC

undercoverage

2024-09-13 11:07:26 UTC

some consumers will shop online，this will cause the representation sample bias

They ignore the people who don't shop at this shopping mall, maybe they choose to shop at other shopping malls or by other ways.

3036340951 — 2024-09-13 11:07:33 UTC

Undercoverage

3036341852 — 2024-09-13 11:07:35 UTC

Because the survey neglects the people who are not a fan to go to the shopping mall.

3036341278 — 2024-09-13 11:07:40 UTC

Only include the people that used to go shopping at shopping mall, ignore other ways to buy things. (supermarket, online, etc.

3036340810 — 2024-09-13 11:07:40 UTC

The shopping mall may not be able to get an accurate result because those people who do not go to shopping mall cannot complete this survey. The sample cannnot be representative.

3036341826 — 2024-09-13 11:07:41 UTC

Those people in shopping mall can't represent all groups of people. Many people buy things online.

3036348020 — 2024-09-13 11:07:41 UTC

This survey will only be given to those who like to do shopping in the shopping mall, which ignores other shopping channels.

3036347624 — 2024-09-13 11:07:42 UTC

People shopping online or in the small store won’t get access to the survey.

2024-09-13 11:07:46 UTC

undercovereage,because they ignore people buy online.

3036348654 — 2024-09-13 11:07:47 UTC

They ignore those people who shop online.

Undercovereage

3036340652 — 2024-09-13 11:07:48 UTC

It may lead to a problem of undercovereage data since some people will shop online instead of going to the mall

3036342301 — 2024-09-13 11:07:48 UTC

people who appear at the shopping mall usually loves shopping below the line while the others love shopping online.

3036340406 — 2024-09-13 11:07:50 UTC

they assumes that the respondents in that shopping mall could represent all customers online and different kinds of shopping mall.

3036341735 — 2024-09-13 11:07:54 UTC

They just send out surveys at only one shopping mall which cannot represent all shopping malls in the area. This might be a sample bias

3036341840 — 2024-09-13 11:07:54 UTC

A shopping mall represents only one choice through which customers can go shopping

wangsihan5600 — 2024-09-13 11:07:55 UTC

Some people would not go to the shopping mall for shopping. And a single shopping mall could not represent the shopping behaviors of people.

3036340614 — 2024-09-13 11:07:57 UTC

some people buy online and only one shopping mall can not represent the result

3036343551 — 2024-09-13 11:07:59 UTC

They only chose the people who are willing to do some shopping at a shopping mall as their surveys' sample.

3036341424 — 2024-09-13 11:08:01 UTC

The public include the people who shop online, in convenience stores, in shopping mall and so on.

Undercovereage bias

3036342442 — 2024-09-13 11:08:01 UTC

The sample only includes the people who preferring shopping at the mall.

3036341541 — 2024-09-13 11:08:03 UTC

Malls may not be representative of the broader population, as certain demographic groups may be over- or under-represented.

2024-09-13 11:08:04 UTC

The data collection is incomplete, and people who buy from other ways are not counted

3036342832 — 2024-09-13 11:08:05 UTC

Volunteers who do a survey at a shopping mall represent volunteers who would go shopping, but they cannot represent those who don’t go to a shopping mall.

3036341723 — 2024-09-13 11:08:05 UTC

they may not choose people from different ages, which have different preference when choosing things

undercoverage

3036341101 — 2024-09-13 11:08:07 UTC

3036342076 — 2024-09-13 11:08:07 UTC

Not all of people will answer the survey, the people answer the survey means they are interested into the topic.

Voluntary Response Bias

3036343525 — 2024-09-13 11:08:11 UTC

The people who are interested in online shopping are not considered.

It ignored those people who do not attend shopping mall

3036341711 — 2024-09-13 11:08:11 UTC

The researchers should choose to send surveys at a variety of shopping malls, to avoid sample bias and increase sampling size.

3036342210 — 2024-09-13 11:08:13 UTC

2024-09-13 11:08:13 UTC

The shoping mall cannot accurately represent all the shopping venues that people do shopping.

3036341890 — 2024-09-13 11:08:17 UTC

Only people shop at the shopping mall are involved.

3036342557 — 2024-09-13 11:08:17 UTC

The type and geographical location of the shopping centre, or the deviation of the survey time, such as weekdays or holidays

There are other ways to shopping

3036348848 — 2024-09-13 11:08:20 UTC

3036342507 — 2024-09-13 11:08:22 UTC

Doesn't include all consumers.

Undercovereage

3036340494 — 2024-09-13 11:08:23 UTC

3036341371 — 2024-09-13 11:08:24 UTC

People who shopping online will be ignored, and the type of shopping mall will also cause sample bias

3036340949 — 2024-09-13 11:08:24 UTC

The shoppers in that mall is not representative enough for shopping behavior

3036345468 — 2024-09-13 11:08:26 UTC

The researchers only select samples that exhibit a behavior pattern on going to shopping mall and therefore have selective bias.

3036166745 — 2024-09-13 11:08:26 UTC

Exclude the buyers who are not willing to answer the survey.

3036342624 — 2024-09-13 11:08:26 UTC

ignore those people who shop online and don't buy things in this shopping mall.

undercoverage

3036342961 — 2024-09-13 11:08:27 UTC

Actually there are many people choose to purchase items online instead of offline

Undercoverage

3036341668 — 2024-09-13 11:08:31 UTC

not everyone shopping at shopping malls

3036342703 — 2024-09-13 11:08:31 UTC

Ignore people buying online or who prefer cheaper shopping site. (Under coverage)

3036342090 — 2024-09-13 11:08:34 UTC

undercoverage: a single shopping mall is too small a sample base. Online shopping is not involved

3036342753 — 2024-09-13 11:08:35 UTC

Shoppers who spend more time in shopping centres are more likely to be selected for the survey

3036344189 — 2024-09-13 11:08:38 UTC

Undercoverage. It ignores the group of people who shop online, thus failing to represent the population.

3036341199 — 2024-09-13 11:08:38 UTC

the sample only covers populations that shopping at a mall

3036342765 — 2024-09-13 11:08:39 UTC

researchers sent the survey in shopping mall, which means the people who answer the research like to go to the shopping mall, then this research cannot collect the information from those who don't like to go to the shopping mall.

Undercoverage

3036341955 — 2024-09-13 11:08:39 UTC

The sample would be limited to the customers that choose to come to this certain shopping mall, or the people would be more willing to go to a shopping mall for shopping. That would cause biases in sample selection.

3036343410 — 2024-09-13 11:08:39 UTC

There will be undercoverage bias.

Shopping mall is not a place where all kinds of customers will come.

Undercoverage

3036343484 — 2024-09-13 11:08:43 UTC

Data from only one mall is not enough. Purchases don’t occur only at shopping mall.

2024-09-13 11:08:43 UTC

people at the mall tend to shop physically but there is a selection bias where people shop online are ignored

The sample cannot represent the whole population, as people who prefer to do shopping online would not show up at the shopping mall.

3036440755 — 2024-09-13 11:08:44 UTC

3036343537 — 2024-09-13 11:08:44 UTC

The researchers could not collect data on shopping behaviors from consumers who like online shopping.

3036160404 — 2024-09-13 11:08:54 UTC

assuming everyone of the public shops at the shopping mall

3036348537 — 2024-09-13 11:08:58 UTC

People who are not at this particular mall will not be able to attend the survey. Others also will prefer to shop online and they also will not be tested from the survey.

3036343927 — 2024-09-13 11:08:58 UTC

Didn't cover people who are not in favour of shopping mall

3637663 — 2024-09-13 11:08:59 UTC

The survey only contains a specific and limited population,ignoring other situation offline and online.

3036341058 — 2024-09-13 11:09:00 UTC

online shoppers are not included in the survey

2024-09-13 11:09:07 UTC

Not all people visit mall, they cannot represent the whole public

3036340705 — 2024-09-13 11:09:09 UTC

can't represent all shopping people

3036441846 — 2024-09-13 11:09:09 UTC

only get information from offline customer, ignore the customer who like shopping online.
not everyone like to do the survey when shopping, the data may limited

conniexiao14 — 2024-09-13 11:09:10 UTC

For those people who like to shop online should not be include in the sample. And the surveys for one shopping mall is not representative.

3036341280 — 2024-09-13 11:09:10 UTC

Conducting surveys at a shopping mall introduces convenience sampling bias and voluntary response bias, as the sample may not represent those who don't frequent malls and those more interested in shopping are more likely to participate.

people who prefer to shop in other types of site are not included

3036159493 — 2024-09-13 11:09:21 UTC

3036342715 — 2024-09-13 11:09:25 UTC

When conducting surveys in shopping malls, researchers might face biases such as time sampling bias (shoppers differ at various times of the month), length bias (those who stay longer are more likely to be surveyed), and selection bias (interviewers may choose respondents like themselves). To reduce these biases, it's important to use systematic sampling methods that represent the actual flow and demographic profile of shoppers throughout the entire month.

2024-09-13 11:09:36 UTC

The sample they capture is limited in the specific shopping mall

3036341670 — 2024-09-13 11:09:47 UTC

only individuals who buy products in the shopping malls are included, those who prefer offline shopping are excluded.

The sample may not be representative of the general public's shopping behaviors, as it excludes people who do not shop at malls, those who are unable to physically visit the mall due to factors such as mobility issues or distance, and those who may shop online instead.

3036347856 — 2024-09-13 11:09:51 UTC

3036342167 — 2024-09-13 11:09:57 UTC

There is an undercovereage since not all of the people who like shopping are shopping offline or just shopping in the certain shopping mall.

3036347777 — 2024-09-13 11:10:04 UTC

Mall shoppers may not be representative of the general population, as certain demographic groups may be more or less likely to visit malls. Researchers should consider the demographic makeup of their sample and weight their results accordingly.

2024-09-13 11:10:26 UTC

Absence Of data of those who doesn’t go shopping at shopping mall

dddaijxuan — 2024-09-13 11:11:01 UTC

there are limited for the people who go to the specific shopping mall

3036341242 — 2024-09-13 11:14:16 UTC

The sample is limited to individuals who visit the mall, which might not represent people who prefer online shopping or who do not visit malls frequently.

3036341412 — 2024-09-13 11:18:24 UTC

People doing that survey in the shoppingmall are bias to do shopping activities rather than don't willing to shop