**Sampling**

For "Sports Participation in 2011," an online panel of more than 55,000 households maintained by TNS was used. The panel is balanced on a number of characteristics determined to be key indicators of general purchase behavior, including household size and composition, household income, age of household head, region and market size. Please note race and ethnicity are not the key indicators of general purchase behavior, and thus African Americans and Hispanics are somewhat underrepresented in the sample.

2010 was the first year that an online survey methodology was used for collecting data on sports participation. Prior to 2010, this annual study was conducted using a mailback survey methodology. Readers should keep this in mind when making direct comparisons with data published prior to 2010.

**Questionnaire**

In January 2012, sample members of the TNS panel were invited to complete the sports participation survey online. Respondents were asked to identify up to three other household members ages seven or older, indicate their age and gender, and provide the number of days of participation for each sport in 2011.

In order to reduce a bias effect that is possible from the order in which the sports were listed, the list was shown in alphabetic order to half of the households, and in reverse-alphabetic order to the remaining half of households.

**Returns**

The study results are based on over 25,000 individuals in these households who are age 7 and older.

In order to ensure returns were representative of the U.S., a 3,264-cell weight matrix was used. The demographic characteristics used in the weight matrix were: state of residence, household income, population density, and presence of children in the household.

The returns were then projected to 280,834,000 - the U.S. population age 7 and older in 2011. A 16-cell age/gender weight matrix was used to project the weighted sample to correctly represent the actual age and gender distribution of the U.S. population.

**Participants**

A participant is defined as an individual seven years of age or older who participates in a sport more than once a year for all sports except aerobic exercising, bicycle riding, exercise walking, exercise with equipment, running/jogging, swimming, weightlifting, and workout at club. For these fitness activities, participation is defined as six times or more during the year.

Note that this study also reports separately the number of individuals who participated "1 Day Only in 2011" or "1-5 Days in 2011" for each sport. These are not included in "Total Respondents in 2011" for each sport since they are not "participants" as defined above.

**Statistical Notes**

It is important to note that in basing estimates of a population on a sample drawn from that population, a degree of sampling error is possible. While a number of biases can affect the extent of sampling error, it is to a great degree dependent on the size of the sample. The larger the sample, the more closely the estimate represents the total population.

Sampling error also affects samples of the same size. A sample drawn from a population will result in an estimate for a characteristic of the population, the proportion of archers for example. If another sample were drawn, it would be likely to include different members of the population. This would yield a slightly different estimate of the proportion of archers. To allow judgments and decisions to be made with confidence when using samples, we can determine a confidence interval for the estimate.

A confidence interval is simply a range. A 95% confidence interval for the proportion of archers in the population is a range in which the estimates for the proportion of archers would fall 95% of the time, were the study to be done repeatedly. For example, in a particular year, the proportion of respondents who stated they participated in archery may be 2.3% (after weighting and projection). Thus, if we were to estimate the proportion of archers in the United States using 100 similar studies, 95 of those studies would yield an estimate within 95% confidence interval of 2.2%-2.4% (+/-0.1%) from the stated proportion.

The confidence interval for measurement of the proportion of participants in each sport does not exceed +/-1.0%.

**Additional Information**

More detailed information on the sports in the survey is available from the NSGA Research Department. For information on the reports available, their contents and costs, please access our online order form.