Most frequently used method of collecting first time data

When faced with a research problem, you need to collect, analyze and interpret data to answer your research questions. Examples of research questions that could require you to gather data include how many people will vote for a candidate, what is the best product mix to use and how useful is a drug in curing a disease. The research problem you explore informs the type of data you’ll collect and the data collection method you’ll use. In this article, we will explore various types of data, methods of data collection and advantages and disadvantages of each. After reading our review, you will have an excellent understanding of when to use each of the data collection methods we discuss.

Types of Data

Quantitative Data

Data that is expressed in numbers and summarized using statistics to give meaningful information is referred to as quantitative data. Examples of quantitative data we could collect are heights, weights, or ages of students. If we obtain the mean of each set of measurements, we have meaningful information about the average value for each of those student characteristics.

Qualitative Data

When we use data for description without measurement, we call it qualitative data. Examples of qualitative data are student attitudes towards school, attitudes towards exam cheating and friendliness of students to teachers. Such data cannot be easily summarized using statistics.

Primary Data

When we obtain data directly from individuals, objects or processes, we refer to it as primary data. Quantitative or qualitative data can be collected using this approach. Such data is usually collected solely for the research problem to you will study. Primary data has several advantages. First, we tailor it to our specific research question, so there are no customizations needed to make the data usable. Second, primary data is reliable because you control how the data is collected and can monitor its quality. Third, by collecting primary data, you spend your resources in collecting only required data. Finally, primary data is proprietary, so you enjoy advantages over those who cannot access the data.

Despite its advantages, primary data also has disadvantages of which you need to be aware. The first problem with primary data is that it is costlier to acquire as compared to secondary data. Obtaining primary data also requires more time as compared to gathering secondary data.

Secondary Data

When you collect data after another researcher or agency that initially gathered it makes it available, you are gathering secondary data. Examples of secondary data are census data published by the US Census Bureau, stock prices data published by CNN and salaries data published by the Bureau of Labor Statistics.

One advantage to using secondary data is that it will save you time and money, although some data sets require you to pay for access. A second advantage is the relative ease with which you can obtain it. You can easily access secondary data from publications, government agencies, data aggregation websites and blogs. A third advantage is that it eliminates effort duplication since you can identify existing data that matches your needs instead of gather new data.

Despite the benefits it offers, secondary data has its shortcomings. One limitation is that secondary data may not be complete. For it to meet your research needs, you may need to enrich it with data from other sources. A second shortcoming is that you cannot verify the accuracy of secondary data, or the data may be outdated. A third challenge you face when using secondary data is that documentation may be incomplete or missing. Therefore, you may not be aware of any problems that happened in data collection which would otherwise influence its interpretation. Another challenge you may face when you decide to use secondary data is that there may be copyright restrictions.

Now that we’ve explained the various types of data you can collect when conducting research, we will proceed to look at methods used to collect primary and secondary data.

Methods Employed in Primary Data Collection

When you decide to conduct original research, the data you gather can be quantitative or qualitative. Generally, you collect quantitative data through sample surveys, experiments and observational studies. You obtain qualitative data through focus groups, in-depth interviews and case studies. We will discuss each of these data collection methods below and examine their advantages and disadvantages.

Sample Surveys

A survey is a data collection method where you select a sample of respondents from a large population in order to gather information about that population. The process of identifying individuals from the population who you will interview is known as sampling.

To gather data through a survey, you construct a questionnaire to prompt information from selected respondents. When creating a questionnaire, you should keep in mind several key considerations. First, make sure the questions and choices are unambiguous. Second, make sure the questionnaire will be completed within a reasonable amount of time. Finally, make sure there are no typographical errors. To check if there are any problems with your questionnaire, use it to interview a few people before administering it to all respondents in your sample. We refer to this process as pretesting.

Using a survey to collect data offers you several advantages. The main benefit is time and cost savings because you only interview a sample, not the large population. Another benefit is that when you select your sample correctly, you will obtain information of acceptable accuracy. Additionally, surveys are adaptable and can be used to collect data for governments, health care institutions, businesses and any other environment where data is needed.

A major shortcoming of surveys occurs when you fail to select a sample correctly; without an appropriate sample, the results will not accurately generalize the population.

Ways of Interviewing Respondents

Once you have selected your sample and developed your questionnaire, there are several ways you can interview participants. Each approach has its advantages and disadvantages.

In-person Interviewing

When you use this method, you meet with the respondents face to face and ask questions. In-person interviewing offers several advantages. This technique has excellent response rates and enables you to conduct interviews that take a longer amount of time. Another benefit is you can ask follow-up questions to responses that are not clear.

In-person interviews do have disadvantages of which you need to be aware. First, this method is expensive and takes more time because of interviewer training, transport, and remuneration. A second disadvantage is that some areas of a population, such as neighborhoods prone to crime, cannot be accessed which may result in bias.

Telephone Interviewing

Using this technique, you call respondents over the phone and interview them. This method offers the advantage of quickly collecting data, especially when used with computer-assisted telephone interviewing. Another advantage is that collecting data via telephone is cheaper than in-person interviewing.

One of the main limitations with telephone interviewing it’s hard to gain the trust of respondents. Due to this reason, you may not get responses or may introduce bias. Since phone interviews are generally kept short to reduce the possibility of upsetting respondents, this method may also limit the amount of data you can collect.

Online Interviewing

With online interviewing, you send an email inviting respondents to participate in an online survey. This technique is used widely because it is a low-cost way of interviewing many respondents. Another benefit is anonymity; you can get sensitive responses that participants would not feel comfortable providing with in-person interviewing.

When you use online interviewing, you face the disadvantage of not getting a representative sample. You also cannot seek clarification on responses that are unclear.

Mailed Questionnaire

When you use this interviewing method, you send a printed questionnaire to the postal address of the respondent. The participants fill in the questionnaire and mail it back. This interviewing method gives you the advantage of obtaining information that respondents may be unwilling to give when interviewing in person.

The main limitation with mailed questionnaires is you are likely to get a low response rate. Keep in mind that inaccuracy in mailing address, delays or loss of mail could also affect the response rate. Additionally, mailed questionnaires cannot be used to interview respondents with low literacy, and you cannot seek clarifications on responses.

Focus Groups

When you use a focus group as a data collection method, you identify a group of 6 to 10 people with similar characteristics. A moderator then guides a discussion to identify attitudes and experiences of the group. The responses are captured by video recording, voice recording or writing—this is the data you will analyze to answer your research questions. Focus groups have the advantage of requiring fewer resources and time as compared to interviewing individuals. Another advantage is that you can request clarifications to unclear responses.

One disadvantage you face when using focus groups is that the sample selected may not represent the population accurately. Furthermore, dominant participants can influence the responses of others.

Observational Data Collection Methods

In an observational data collection method, you acquire data by observing any relationships that may be present in the phenomenon you are studying. There are four types of observational methods that are available to you as a researcher: cross-sectional, case-control, cohort and ecological.

In a cross-sectional study, you only collect data on observed relationships once. This method has the advantage of being cheaper and taking less time as compared to case-control and cohort. However, cross-sectional studies can miss relationships that may arise over time.

Using a case-control method, you create cases and controls and then observe them. A case has been exposed to a phenomenon of interest while a control has not. After identifying the cases and controls, you move back in time to observe how your event of interest occurs in the two groups. This is why case-control studies are referred to as retrospective. For example, suppose a medical researcher suspects a certain type of cosmetic is causing skin cancer. You recruit people who have used a cosmetic, the cases, and those who have not used the cosmetic, the controls. You request participants to remember the type of cosmetic and the frequency of its use. This method is cheaper and requires less time as compared to the cohort method. However, this approach has limitations when individuals you are observing cannot accurately recall information. We refer to this as recall bias because you rely on the ability of participants to remember information. In the cosmetic example, recall bias would occur if participants cannot accurately remember the type of cosmetic and number of times used.

In a cohort method, you follow people with similar characteristics over a period. This method is advantageous when you are collecting data on occurrences that happen over a long period. It has the disadvantage of being costly and requiring more time. It is also not suitable for occurrences that happen rarely.

The three methods we have discussed previously collect data on individuals. When you are interested in studying a population instead of individuals, you use an ecological method. For example, say you are interested in lung cancer rates in Iowa and North Dakota. You obtain number of cancer cases per 1000 people for each state from the National Cancer Institute and compare them. You can then hypothesize possible causes of differences between the two states. When you use the ecological method, you save time and money because data is already available. However the data collected may lead you to infer population relationships that do not exist.

Experiments

An experiment is a data collection method where you as a researcher change some variables and observe their effect on other variables. The variables that you manipulate are referred to as independent while the variables that change as a result of manipulation are dependent variables. Imagine a manufacturer is testing the effect of drug strength on number of bacteria in the body. The company decides to test drug strength at 10mg, 20mg and 40mg. In this example, drug strength is the independent variable while number of bacteria is the dependent variable. The drug administered is the treatment, while 10mg, 20mg and 40mg are the levels of the treatment.

The greatest advantage of using an experiment is that you can explore causal relationships that an observational study cannot. Additionally, experimental research can be adapted to different fields like medical research, agriculture, sociology, and psychology. Nevertheless, experiments have the disadvantage of being expensive and requiring a lot of time.

Summary

This article introduced you to the various types of data you can collect for research purposes. We discussed quantitative, qualitative, primary and secondary data and identified the advantages and disadvantages of each data type. We also reviewed various data collection methods and examined their benefits and drawbacks. Having read this article, you should be able to select the data collection method most appropriate for your research question. Data is the evidence that you use to solve your research problem. When you use the correct data collection method, you get the right data to solve your problem.

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