To illustrate the use of smartphone-based data collection， consider a forthcoming study that combined queries embedded in everyday life with sensor data to paint a more accurate picture of how mood is affected by a person’s location. The data for the study came from more than 12，000 members of the general public who downloaded a free Android app to participate in the research. Twice during the day， they were prompted to report their mood and location， with location information additionally collected from the phone‘s location sensors. Using both kinds of location data， the study found that people reported significantly more positive moods in locations that typically involve social interactions (such as a café or friend’s house) than at home， and more positive moods at home than at work.

　　Other studies have used sensor data to draw more subtle kinds of inferences. For instance， a study published in 2015 followed 48 students over the course of a 10-week school term. Using a combination of location， activity and audio sensors， the researchers could infer students‘ patterns of class attendance， study time， physical activity and socializing. These variables， in turn， predicted student GPA with surprisingly high accuracy. Another 2015 study used mobile phones to track 40 adult participants over a two-week period. Using patterns of movement and phone usage， the researchers were able to identify behaviors that predicted symptoms of depression.

　　These studies are just first steps. As more data are collected and methods for analysis improve， researchers will be in a better position to identify how different experiences， behaviors and environments relate to each other and evolve over time， with the potential to improve people’s productivity and wellbeing in a variety of domains. Beyond revealing population-wide patterns， the right combination of data and analysis can also help individuals identify unique characteristics of their own behavior， including conditions that could indicate the need for some form of intervention - such as an uptick in behaviors that signal a period of depression.

　　Smartphone-based data collection comes at an opportune time in the evolution of psychological science. Today， the field is in transition， moving away from a focus on laboratory studies with undergraduate participants towards more complex， real-world situations studied with more diverse groups of people. Smartphones offer new tools for achieving these ambitions， offering rich data about everyday behaviors in a variety of contexts.

　　So here‘s another way in which smartphones might transform the way we live and work： by offering insights into human psychology and behavior and， thus， supporting smarter social science.

　　51. What does the author say about the negative impact of smartphones？

　　A. It has been overshadowed bythepositive impact.