* Institution type: Four-year public universities, four-year private universities, and community colleges all have different dropout rates. Community colleges tend to have higher attrition rates.
* Student demographics: Factors like socioeconomic status, race, and first-generation college student status significantly impact persistence.
* Academic preparation: Students who enter college underprepared academically are at higher risk of dropping out.
* Definition of "dropout": The definition of "dropping out" can vary. Some institutions count students who withdraw as dropouts, while others only count those who never return. The timeframe is also a consideration (e.g., after one year, after two years).
While precise figures for *sophomores specifically* are hard to come by, studies generally show that the overall first-year attrition rate (students who don't return for a second year) is considerably higher than the subsequent years' rates. Therefore, the percentage of sophomores who drop out is *lower* than the first-year dropout rate, but still significant.
To find data relevant to a specific institution or student population, you would need to consult that institution's retention and graduation rates or relevant research studies focusing on that specific group. National averages are generally reported for first-year retention, and don't usually break down the attrition rate by sophomore year specifically.