All good thinkers and writers go through a process of finding and using sources to inform their thinking.

If I have seen further than others, it is by standing upon the shoulders of giants.
—Isaac Newton

For instance, author Jane McGonigal writes about video games and how we can use them to solve serious problems in the real world. One of the things video games do very well is urge us to play more, and in her book Reality Is Broken: Why Games Make Us Better and How They Can Change the World, McGonigal explores how we might harness that power. The question is, how do video games motivate us? To answer that, McGonigal considered the work of several psychologists, including research that Sonja Lyubomirsky reported in her book The How of Happiness. Here’s a passage from that book; as you read it, think about how Lyubomirsky’s ideas might apply to the realm of video games.

The media are constantly telling us about the latest newfangled strategy shown to “really” work in boosting health and well-being. These strategies keep changing, each one evidently bested by the next, such that every new pronouncement becomes harder to believe. If the new kind of yoga or meditation or marital therapy technique were as effective as the reports claim, then wouldn’t everyone be doing it and benefiting from it? Well, no. Any major life-changing endeavor must be accompanied by considerable sustained effort, and I would speculate that the majority of people do not or cannot continue putting out that kind of effort. What’s more, all new happiness-enhancing or health-boosting strategies have something in common; each one bestows on the person a specific goal, something to do and to look forward. Moreover, as I explain later on, having goals in and of themselves is strongly associated with happiness and life satisfaction. That’s why — at least for a time — any new happiness strategy does work!

Now, let’s examine how McGonigal draws on Lyubomirsky’s ideas and uses them to inform her argument about video games, specifically World of Warcraft (WoW):

When you’re on a WoW quest, there’s never any doubt about what you’re supposed to do or where or how. It’s not a game that emphasizes puzzle solving or trial-and-error investigation. You simply have to get the job done, and then you will collect your reward.

Why do we crave this kind of guaranteed productivity? In The How of Happiness, Sonja Lyubomirsky writes that the fastest way to improve someone’s everyday quality of life is to “bestow on the person a specific goal, something to do and to look forward.” When a clear goal is attached to a specific task, she explains, it gives us an energizing push, a sense of purpose. That’s why receiving more quests every time we complete one in World of Warcraft is more of a reward than the experience points and the gold we’ve earned. Each quest is another clear goal with actionable steps.

Lyubomirsky may not be writing about video games per se, but her research on the relationship between goals and personal satisfaction lends authority to McGonigal’s analysis of how video games motivate players. Could McGonigal have made her point without citing this source? Certainly, but bringing in an expert adds credibility and shows that McGonigal is an active participant in a scholarly and ongoing conversation on her topic.

Notice how McGonigal uses this source—she doesn’t just drop in a quote. She begins with a summary of Lyubormirsky’s larger ideas, and places the quote in that context. McGonigal introduces the quote by acknowledging the source, and finds a way to incorporate the quote smoothly into her own sentence. Then McGonigal follows up with an explanation of how that quote and idea apply to the point she’s making about video games, and WoW in particular. This commentary ensures that McGonigal’s ideas remain central and that the quotation is serving the purpose she wants it to serve. What we’ve just described are the primary steps to integrating quotations: