System for Observing Play and Leisure Activity in Youth (SOPLAY)

Abstract

The System for Observing Play and Leisure Activity in Youth (SOPLAY) is a behavioral assessment instrument designed to quantify physical activity (PA) levels and contextual factors in designated “open” environments, such as schoolyards or recreational facilities. It relies on momentary time sampling techniques, involving systematic and periodic visual scans of pre-determined target areas. Observers mechanically or electronically code the activity of each individual as Sedentary (lying down, sitting, or standing), Walking, or Very Active. Separate scans are conducted for males and females, along with simultaneous recording of environmental variables (e.g., supervision, equipment, accessibility). SOPLAY provides summary counts of participants in various activity states, allowing for the calculation of setting-specific energy expenditure rates (Kcal/kg/min) and comparisons across different environments or time periods.

Keywords

SOPLAY, systematic observation, physical activity measurement, youth leisure, environmental assessment, momentary time sampling, energy expenditure.

Authors

Thomas L. McKenzie, Ph.D.

Purpose

The primary purpose of SOPLAY is to obtain objective observational data regarding the number of students present and their corresponding physical activity levels during unstructured play and leisure periods within specified activity areas. This methodology was developed to overcome limitations associated with quantifying activity in “open” environments, where both participant numbers and activity intensity fluctuate rapidly.

The scale allows researchers and practitioners to assess environmental factors—such as area accessibility, usability, supervision, organization, and equipment availability—simultaneously with behavioral observations. This integrated approach facilitates the analysis of how specific environmental contexts influence youth PA engagement during periods like before school (BS), lunchtime (L), and after school (AS).

Construct

SOPLAY primarily measures the construct of Observed Physical Activity Intensity, categorized into three levels: Sedentary (S), Walking (W), and Very Active (V). These categories are assigned based on direct observation during momentary scans and are used to estimate physiological output via calculated energy expenditure rates. The secondary, but equally critical, construct measured is the Contextual Environment, encompassing key variables that may moderate or facilitate PA opportunities, such as the presence of supervision or organized activities, and the physical characteristics of the observation area.

Validity

While a definitive field-based validity study specific to the SOPLAY measure in its entirety has not been conducted, the validity of its core activity codes (Sedentary, Walking, Very Active) has been established through concurrent measurement using heart rate monitoring (McKenzie et al., 1991; Rowe, Schuldheism, & van der Mars, 1997). These foundational studies provide empirical support for the initial construct validity of SOPLAY, demonstrating that the observational codes accurately reflect physiological measures of exertion. The momentary time sampling technique itself is considered valid for persistent behaviors, provided that measures are taken frequently and randomly.

Reliability

Reliability data for SOPLAY were collected during 14 days of field assessment involving pairs of assessors making simultaneous and independent counts. The reliability of the contextual variables was excellent, with interobserver agreements (IOA) ranging from 88% to 97% for factors such as area accessibility, usability, supervision, organized activity presence, and equipment provision.

Reliability for the activity counts was assessed using intraclass correlations (R). Correlations were high for sedentary girls (R=.98) and walking girls (R=.95), and similarly high for boys across all categories: sedentary (R=.98), walking (R=.98), and very active (R=.97). While the correlation for very active girls (R=.76) was slightly lower than other categories, all measures met the acceptable criterion (IOA=80%, R=.75) for reliable assessment in field settings.

Factor Analysis

Factor analysis is not applicable to SOPLAY. SOPLAY is a direct behavioral observation instrument that categorizes observed activity based on pre-defined intensity criteria (Sedentary, Walking, Very Active) rather than being a psychometric scale requiring the extraction of latent constructs.

Instrument

Test Type: Direct Behavioral Observation System

Format: Field observation using momentary time sampling; requires trained observers, mechanical/electronic counters, and standardized recording forms.

Language Available: English (The coding system relies on behavioral categorization and numerical codes, minimizing linguistic dependence).

Population Group: Youth (Children and Adolescents)

Age Group: Typically utilized in school and community settings (K-12, or youth leisure settings).

Population Details: Students or youth observed during non-structured time (recess, lunch, before/after school) or in general recreational environments.

Test Methodology: Observers systematically scan predetermined Target Areas (which may be subdivided into Scan Spaces) and tally the number of males and females engaged in Sedentary, Walking, or Very Active behaviors, while concurrently recording five key environmental conditions (Accessibility, Usability, Supervision, Organized Activity, and Equipment).

Keywords

Youth exercise, leisure activity, school environment, observational method, psychometrics, heart rate monitoring, physical education, objective assessment.

Authors

Author ORCID Identifier: Not provided in source.

Affiliation Email addresses: [email protected]

Correspondence Address: Professor, Department of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA 92182

Permissions & Fee and Test Year

Test Year: Initial development and key validation studies occurred between 1991 and 2000.

Permissions and Fee: The instrument and its procedures manual are typically made available for research purposes through the author or affiliated research centers. A resource DVD titled “Systematic Observation: SOPLAY/SOPARC Introduction, Practice, and Assessment” (McKenzie, 2005) is available from Active Living Research (www.activelivingresearch.org). Users are advised to contact the primary author, Thomas L. McKenzie, for formal permissions and current usage guidelines.

Reference’s

1. McKenzie, T. L., Marshall, S. J., Sallis, J. F., & Conway, T. L. (2000). Leisure-time physical activity in school environments: An observational study using SOPLAY. Preventive Medicine, 30, 70-77.

2. McKenzie, T. L., Sallis, & Nader, P. R. (1991). SOFIT: System for observing fitness instruction time. Journal of Teaching in Physical Education, 11, 195-205.

3. Rowe, P.J., Schuldheisz, J.M., & van der Mars, H. (1997). Measuring physical activity in physical education: Validation of the SOFIT direct observation instrument for use with first to eighth grade students. Pediatric Exercise Science, 9(2), 136-149.

4. Sallis, J. F., Conway, T. L., Prochaska, J. J., McKenzie, T. L., Marshall, S. & Brown, M. (2001). School environments are associated with youth physical activity. American Journal of Public Health, 91, 618-620.

5. McKenzie, T. L. (2005, November). Systematic Observation: SOPLAY/SOPARC Introduction, Practice, and Assessment. (27 minute DVD). San Diego State University, San Diego, California. Available from Active Living Research, San Diego State University, 3900 Fifth Avenue, Suite 310, San Diego, CA 92103 (www.activelivingresearch.org) or the author.

Items of the System for Observing Play and Leisure Activity in Youth (SOPLAY)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

SOPLAY (System for Observing Play and Leisure Activity in Youth)

Obs. ID #:_______________ Reliability: 0. No 1. Yes Temp:_______________F Period: 1. BS 2. L1s1 L1s2 3. L2s1 L2s2 4. L

Activity Codes:

• 0=No identifiable activity
• 1=Aerobics
• 2=Baseball/Softball
• 3=Basketball
• 4=Dance
• 5=Football
• 6=Gymnast
• 8=Racquet sports
• 9=Soccer
• 10=Swimming
• 11=Volleyball
• 12=Weight Training
• 13=Other playground games
• 14=No

Physical activity codes for secondary schools:

1. no specific activity (sit, stand, walk)
2. aerobics (dance, step aerobics) racquet sports (tennis, badminton)
3. baseball/softball      soccer
4. basketball swimming
5. dance (ballet, country, line) volleyball
6. football weight training/lifting
7. gymnastics playground games (e.g., tetherball, 4-square)
8. martial arts (judo, karate) none of the activities above (e.g., track) Comments. Describe any events or features that may help explain any of the above data.

Alternative physical activity codes for young children:

1. no specific activity (sit, stand, walk)          jumping games
2. fitness/aerobics (dance/step aerobics)          manipulative games/racquet activities
3. baseball/softball          sedentary games/activities
4. basketball/volleyball         none of the other ten categories
5. dance/gymnastics         tag/chasing games
6. soccer/football
7. climbing/sliding

Key Words (Operational Definitions):

• Target Area – A predetermined observation area in which students may potentially engage in physical activity. A number of Target Areas will be established for each school.
• Scan Space – A subdivision of a Target Area in which the assessor makes an observation scan. Target Areas are subdivided into Scan Spaces when the number of students is large and they are engaged actively.
• Scan – A single observation movement from left to right across a Target Area or Scan space. During a sweep, each individual student in the area is counted and coded as being Sedentary (S), Walking (W), or Very Active (V).

Contextual Condition Codes:

• A = Area is accessible (e.g., not locked or rented to others)
• U = Area is usable for physical activity (e.g., is not excessively wet or windy).
• S = Area is supervised by designated school or adjunct (e.g., YMCA) personnel (e.g., teachers, playground supervisors, volunteers). The supervisor must be in or adjacent to that specific area.
• O = Organized physical activity (i.e., scheduled, with leadership by school or agency personnel apparent) is occurring in the area (e.g., intramurals, interscholastic practices, fitness stations).
• E = Equipment provided by the school or other agency is present (e.g., balls, jump ropes). Do not code ‘YES’ if the only equipment is permanent (e.g., basketball hoops) or is owned by students themselves.