Whether you're interested in counting how many friends are coming to a party, finding out what your customers think about a new product line, or how people will vote in the next election, polls are often the most reliable, and often the only reliable way to find out what people think and want.

Another reason for surveys is the desire for "social comparison," which makes us learn about others, and surveys are the best way to get that information. In the end, context is more important than anything else.

There are at least four important reasons why people take surveys.

Surveys give specific numbers.

In news articles, polls serve to confirm and reinforce the opinions of the few people who can be quoted in the article. Article stories are much more persuasive if we know that they reflect what is happening to significant masses of people, not just those represented in the article.

Similarly, customer service surveys aim to find out whether a customer complaint is an isolated or widespread occurrence. Similarly, one satisfied customer does not mean that a startup's stock will be in huge demand. Surveys help gauge how representative individual views and impressions are.

Well-done surveys provide accurate data on people's opinions and behaviors that can be used to make important decisions. Just as an aspiring politician is more likely to win an election if he or she understands what voters really want, a youth league team manager is more likely to succeed if he or she can quickly identify problems in the practice program by interviewing coaches and parents.

Polls provide important benchmarks

Surveys are regularly used to make individual decisions -- for example, whether to run a particular advertising campaign or create a new service -- but they become an even more powerful tool if repeated regularly.

Survey researchers often say, "Trend is your friend." After all, if you ask the same question at different times, you get a clear picture of how things change over time.

The U.S. Census itself is a survey (albeit a very large-scale one) and is especially helpful in cataloging major demographic changes in the country, such as the racial composition of the U.S. A company's NPS score may not matter much on its own, but its significant drop two quarters in a row should cause managers to look hard for causes and measures of improvement.

The questions reveal the reasons.

"Big data" is a universal vogue these days. But it's also a big limitation. The term "big data" largely refers to implicit data, or data derived from observing and analyzing your behavior and the behavior of others online and elsewhere.

This data is constantly growing in volume, but it's not omnipotent. Explicit data is simply information that is fully disclosed or expressed without uncertainty or ambiguity.

Explicit data is information obtained directly from an individual, usually using survey methodology. They are inherently more reliable when it comes to uncovering motives for actions. If Amazon had collected some explicit data by asking one simple question, "Do you buy this product as a gift?" they wouldn't have to make useless recommendations to their customers.

Surveys give you a voice

How important polls are can probably best be understood from a book that isn't about polls at all. In his classic book, Quitting, Voice and Loyalty, Princeton economist Albert Hirschman looked at the main types of people's reactions to an inefficient organization: they can either "quit" and go about their business elsewhere, or they can "voice" their dissatisfaction and try to change things from within. How loyal people feel about a cause or company affects whether they decide to "vote with their feet" and leave or speak up.

Hirschman notes that people and companies tend to pay attention to leaving in order to identify a problem. For example, do we have fewer customers than last month? But by the time you see it, it may be too late. Leaving is a lagging indicator.

Any organization succeeds by keeping an eye on the voice, not the care. Empowering customers to voice their comments helps keep them engaged and makes them less likely to decide to spend their time or money elsewhere.

In other words, voice is your canary in the mine.

So let's engage students in surveys to get accurate numbers, benchmarks, uncover reasons and give our respondents a voice.