School Nutrition and Meal Cost Study (SNMCS), SY 2014-15, Volume 3: School Meal Costs and Revenues

These data are from the first nationally representative, comprehensive assessment of the school meal programs since the updated nutrition standards for school meals were phased in beginning School Year 2012-2013. The study results were presented in four volumes summarizing study findings related to (1) foodservice operations, (2) the nutrient content of school meals as offered and served, (3) meal costs and revenues, and (4) student participation, dietary intake and plate waste. The data files presented here correspond to Volume 3 on the cost of school meal operations, including the costs of the meals themselves, as well as revenues of school food authorities.Processing methods and equipment used<br>Study date(s) and durationThe data was collected between January and June 2015 and is representative of School Year 2014-15.<br>Study spatial scale (size of replicates and spatial scale of study area)The data is representative of public School Food Authorities (SFAs), schools, students attending those schools, and their parents in SY 2014-15 within the contiguous 48 states and the District of Columbia.<br>Level of true replication<br>Sampling precision (within-replicate sampling or pseudoreplication)The sampling approach involved first randomly dividing a sampling frame of all public SFAs into three separate sampling groups.<br>Group 1 includes SFAs, but no schools were sampled. SFAs that serve only charter schools were represented in this group. Group 1 SFAs participated in the SFA Director Survey to provide the precision required for estimating SFA characteristics and policies.<br>Group 2 includes SFAs, schools, and students and their parents. Group 2 SFAs participated in the SFA Director, School Nutrition Manager (SNM), and Principal Surveys. Interviews were conducted with students (and their parents) in these schools as well as dietary recalls.<br>Group 3 includes SFAs, schools, and lunch and breakfast observations. A subset of SFAs and schools provided additional data needed to estimate meal costs. Plate waste was observed at a subsample of Group 3 schools.<br>Level of subsampling (number and repeat or within-replicate sampling)<br>Study design (before–after, control–impacts, time series, before–after-control–impacts)Cross-sectional<br>Description of any data manipulation, modeling, or statistical analysis undertakenResults were weighted to be nationally-representative. More information on weighting techniques is available in the final report.<br>Description of any gaps in the data or other limiting factorsOverall, SFAs and schools were very cooperative with weighted response rates for various data collection instruments ranging from 83 to 97 percent. Gaining cooperation from students and parents was more challenging, especially in schools that required active parental consent. Weighted response rates for students and parents ranged from 64 to 89 percent.<br>The data is not representative of Alaska, Hawaii, or US territories. Food prices in these non-contiguous areas are systematically different from those in the 48 contiguous states and District of Columbia.<br>Outcome measurement methods and equipment usedData was collected through interviews with SFA directors and businesses managers, school principals, and school nutrition managers.<br><br>

本数据集源自2012-2013学年起逐步推行学校餐食营养标准更新后，首次针对学校餐食项目开展的全国性代表性综合评估。
该研究成果分为四卷，分别总结了四类研究发现：(1) 餐饮服务运营情况；(2) 供餐及在售学校餐食的营养成分；(3) 餐食成本与营收；(4) 学生参与度、膳食摄入与餐盘剩餐情况。本次提供的数据文件对应第三卷，聚焦学校餐食运营成本，涵盖餐食本身成本及学校食品管理部门（School Food Authorities, SFAs）的营收情况。

所用处理方法与设备

数据采集时段与周期：本数据集采集于2015年1月至6月，代表性覆盖2014-2015学年。

研究空间尺度（重复样本规模与研究区域空间范围）：本数据集代表性覆盖美国本土48州及哥伦比亚特区内2014-2015学年的公立学校食品管理部门（School Food Authorities, SFAs）、学校、在校学生及其家长。

真实重复水平与抽样精度（组内抽样或伪重复）：本次抽样首先将所有公立SFA的抽样框架随机划分为三个独立抽样组。
- 第1组：仅包含SFA，未抽取学校样本。仅服务特许学校的SFA纳入本组。第1组SFA参与了SFA主管调查，以满足估算SFA特征与政策所需的精度要求。
- 第2组：包含SFA、学校、学生及其家长。第2组SFA参与了SFA主管、学校营养经理（School Nutrition Manager, SNM）及校长调查。研究人员对本组学校的学生（及其家长）开展了访谈，并进行了膳食回顾调查。
- 第3组：包含SFA、学校，并开展午餐与早餐供餐观测。部分SFA与学校提供了估算餐食成本所需的补充数据。研究人员在第3组学校的子样本中开展了餐盘剩餐观测。

子抽样水平（抽样数量与重复/组内抽样情况）

研究设计：横断面研究

数据处理、建模与统计分析说明：所有结果均经过加权处理以实现全国代表性。加权方法的详细说明可参见最终研究报告。

数据缺失情况与其他限制因素说明：总体而言，SFA与学校配合度较高，各类数据采集工具的加权响应率介于83%至97%之间。但获取学生与家长的配合难度更大，尤其是在要求获得家长主动同意的学校中。学生与家长的加权响应率介于64%至89%之间。
本数据集不代表阿拉斯加州、夏威夷州及美国海外领地的情况。上述非本土区域的食品价格与美国本土48州及哥伦比亚特区存在系统性差异。

结果测量方法与所用设备：数据通过对SFA主管、业务经理、学校校长及学校营养经理的访谈采集。