Stratified Sampling, PDF

What Is Stratified Sampling?

Stratified sampling (SRS), also known as random quota sampling, is a sampling method that divides the population into homogenous groups. These groups are known as strata, and they complete the sampling procedure. Each stratum is based on comparable features or characteristics, such as race, gender, education level, and wealth. These characteristics vary based on the market research criteria. According to research, most businesses sell to between 5 and 20 percent of new clients but 60 to 70 percent of existing consumers. With so much to gain from excellent customer retention, it is crucial to evaluate your retention rates to determine if you need to put in further effort in this area.

Benefits of Stratified Sampling

When the population is heterogeneous in the variable or trait under study, stratified random sampling is employed to achieve more accurate results. Stratification entails layering or grouping. If you are still interested, the following are some advantages of stratified sampling:

More Representative Sample: A well-designed and carried-out stratified random sampling plan avoid the problems with both purposive and random sampling while keeping both benefits. It divides the universe into homogeneous subgroups based on a purposeful characteristic and then draws samples from each stratum using random sampling. A stratified random sample ensures that each stratum or essential part of the population is well represented and that no important aspect is left out entirely. Stratified random sampling gives a sample more representative of the whole people and, as a result, has less variation than other sampling methods.Greater Precision: Due to the decreased variability within each stratum, stratified random sampling produces more accurate estimates than essential random sampling. For example, the sample estimate of the population mean is more efficient in proportionate and Neyman’s distribution of samples to different strata in stratified random sampling than in simple random sampling.Administrative Convenience: Administrative efficiency is enhanced by subdividing the population into reasonably homogenous groupings. Unlike random samples, stratified samples are anticipated to be geographically localized. This ultimately results in cost and time savings in collecting data, interviewing respondents, and supervising fieldwork.Degrees of Accuracy: On occasion, it is desired to obtain varying degrees of precision for distinct population segments. Stratified random sampling is the only method that allows us to get findings with known accuracy for each stratum.Segment of Population: Quite frequently, the sampling challenges for various population groups vary dramatically. In such a scenario, the problem can be efficiently addressed by stratified sampling by treating each portion of the population as a separate stratum and sampling them independently.

Tips on How to Reach Out to Possible Customers

Customers today are getting pickier about the brands they buy. 84% of millennials don’t trust traditional advertising, which we can’t ignore. Old ways to reach customers work better than they used to. In addition to personal selling, advertising, and sales promotion, marketers need to offer creative content, run a YouTube channel, and promote their brand and marketing on Instagram. Was one of your goals this year to get more people to buy from you? Here are some tips you can follow to bring in more customers.

1. Provide discounts and special offers to new clients.

Today’s consumers continue to seek value and discounts. Offer introductory discounts or promos such as buy two, get one free, or free gift wrapping on the first three transactions to entice new customers. These deals can attract new clients contemplating doing business with you but need the incentive to alter their shopping habits. Then, monitor what they purchase and which offers they redeem so that you may more effectively target them with future marketing messages that will solidify their loyalty.

2. Ask for referrals

Put a customer’s loyalty to work for you by requesting referrals once you have earned them. Existing clients are one of the best avenues for acquiring new ones. But you cannot be passive and expect them to bring in their coworkers, friends, and family. Instead, assume responsibility and develop a method to request referrals from your delighted consumers aggressively. Integrate activities that generate referrals into the sales process. Send follow-up email memos to ensure clients are satisfied with their purchases, and then send another email requesting referrals. Consider adding incentives if the price of the item justifies it.

3. Recontact old customers

Return to your list of lapsed client lists and market to those who still need to do business with you. Create a regular timetable for this (say, every three months) and choose consumers you last saw six months ago. Reach out to them by email, direct mail, text message, or phone with a “We miss you” message and a bargain or promotion in exchange for their return.

4. Network and Update Your Website

There is no better way to increase brand recognition than meeting new people and introducing yourself and your business. Join your industry association, local chamber of commerce, and networking groups. Attend Meetup events. Attending PTA meetings might be a great way to network if you own a local business. Also, consumers and B2B purchasers rely primarily on online searches to discover new firms. Your website must perform the most lifting for clients to locate you. Examine your search engine marketing and optimization practices, ensuring your website is mobile-friendly. Even your site design makes a difference. Too many images might slow your website’s load time, which can be off-putting to visitors. If you need more in-house knowledge, employ a website design business and an SEO professional for assistance.

5. Collaborate with complementary companies

Cooperating with businesses with a similar consumer base but are not direct competitors and planning how to promote to one another’s customers to generate new business is a cost-effective strategy to attract new customers. For example, if you offer baby things, partnering with a company that sells maternity wear might be a terrific idea. In addition, by exhibiting your industry experience, you can build curiosity and even generate buzz, which can help you attract new consumers and obtain additional revenue from your current clientele. You can establish a favorable impression on possible new consumers and clients by volunteering to speak on industry panels, hosting a webinar or workshop, speaking at industry events or to groups your target customers belong to, and hosting educational sessions, to name a few. This strategy is particularly effective for B2B business owners.

6. Benefit from online rating and review sites

Consumers in B2B and B2C markets commonly consult online ratings and review sites before conducting business with a foreign company. Consequently, you must monitor these websites and respond to any complaints. Utilize favorable reviews by including links on your website—post signage in your store, office, restaurant, or other area requesting customer feedback evaluation. New clients are likelier to try your business if they observe others praising it.

How Do You Conduct Stratified Sampling?

To employ stratified sampling, you must be able to divide your population into subgroups that are mutually exclusive and exhaustive. This means that every member of the population may be classified into a single subset. If you assume that subgroups will have different mean values for the variable(s) you’re examining, stratified sampling is the most appropriate probability sampling technique to use. What are the essential steps in stratified sampling?

1. Know All Attributes

Your team should be aware of the attributes (strata) they will compare using stratified sampling. Therefore, they should be mindful of significant segments within the market whose behaviors and traits may generate distinct strata. Consider a scenario where the target audience comprises high school kids, and you wish to determine their preferred reading material. Now, there can be numerous strata, such as gender, age, interest, academic plans, types of teachers, and parental qualifications. In this scenario, these groupings and others will form. We included ‘kind of instructors’ and ‘parents’ qualifications’ because they significantly impact students’ decisions. However, your team must be aware of all target market features to do market research utilizing stratified sampling.

2. Choose Your Special Interest Groups

So, to continue with the same example, if you want to know what kinds of books girls like after considering their parents’ educational level, the study’s strata will be “girls” and “parents’ educational level” out of the whole population. In the same way, “boys” and “parents’ qualifications” can be used as an example. We can make more subgroups based on your market research needs, like only 15-year-old girls or parents with a master’s degree or higher. This way, your sample will be much more in line with what you need for your research. This makes the results more accurate and trustworthy.

3. Finalize The Sample Size

After finalizing distinct samples for distinct combinations of strata and subgroups, you and your team determine the size of these samples. This is determined by examining your study objectives. It depends on the size of the entire population and whether or not the sample sizes are identical (target market). The selection ratio from each stratum, however, will be proportional.

4. Establish a Random Sample

You selected several strata, established further subgroups, and determined the sample size. Calculating the sample size using the stratified sampling formula and forming all samples is all that remains. Remember that if you correctly apply the complete procedure, including the recipe, all models will be mutually exclusive.

5. Survey

After creating all stratified samples, the final stage is to conduct surveys. Some market research survey software permits highly targeted surveys and real-time data analysis for all models. This solution eliminates the requirement for your team to gather and analyze survey findings. They need only choose the appropriate question kinds, personalize them, click send,’ and then wait for the results.


Why is it better to use stratified sampling than simple?

Compared to simple random sampling, stratified sampling has both advantages and downsides. Because it uses specific features to divide the population into subsets, it can provide a more accurate picture of the people.

What is the purpose and application of stratification?

Stratification is classifying data, individuals, and things into separate groups or levels. It is a technique employed alongside other data analysis tools. When data from multiple sources or categories are combined, it might not be easy to discern their significance.

Does stratified sampling reduce bias?

Stratified random sampling allows researchers to become aware of this knowledge before constructing their sample, preventing sampling bias.

Whether you use proportionate or disproportionate stratified sampling, the most important thing is to make subgroups that are the same on the inside. These are different from other sample populations with different strata and subgroups. So, the final sample for complete market research can include a fair number of people from minority groups.