Merge pull request #968 from cmu-delphi/surveys/methodology-report

CTIS methodology report links

Author: krivard

docs/api/covidcast-signals/fb-survey.md

@@ -19,17 +19,18 @@ grand_parent: COVIDcast Epidata API
 
 This data source is based on the [COVID-19 Trends and Impact Survey (CTIS)](../../symptom-survey/)
 run by the Delphi group at Carnegie Mellon.
-Facebook directs a random sample of its users to these surveys, which are
-voluntary. Users age 18 or older are eligible to complete the surveys, and
+Facebook directed a random sample of its users to these surveys, which were
+voluntary. Users age 18 or older were eligible to complete the surveys, and
 their survey responses are held by CMU and are sharable with other health
 researchers under a data use agreement. No individual survey responses are
 shared back to Facebook. See our [surveys
 page](https://delphi.cmu.edu/covid19/ctis/) for more detail about how the
 surveys work and how they are used outside the COVIDcast API.
 
 As of November 2021, the average number of Facebook survey responses we
-receive each day is about 40,000, and the total number of survey responses we
-have received is over 25 million.
+received each day was about 40,000. The survey ran from April 6, 2020 to June
+25, 2022, collecting roughly 29.5 million responses in the United States in that
+time.
 
 We produce several sets of signals based on the survey data, listed and
 described in the sections below:

docs/symptom-survey/coding.md

@@ -13,9 +13,12 @@ provides the full survey text, coding schemes, and history of survey waves and
 revisions.
 
 <div style="background-color:#f5f6fa; padding: 10px 30px;"><strong>Comprehensive
-codebook:</strong> Our <a href="codebook.csv">codebook (CSV)</a> lists all
-questions and answer choices across all waves of the survey. See below for
-details on the <a href="#basic-coding-rules">basic coding rules</a> and the <a
+documentation:</strong> The <a
+href="https://dataforgood.facebook.com/dfg/resources/CTIS-methodology-report">CTIS
+Methodology Report</a> describes the sampling, data collection, and weighting
+process. Our <a href="codebook.csv">codebook (CSV)</a> lists all questions and
+answer choices across all waves of the survey. See below for details on the <a
+href="#basic-coding-rules">basic coding rules</a> and the <a
 href="#comprehensive-codebook">formatting of the codebook</a>, and narrative
 explanations of the reasons for each instrument change.</div>
 

docs/symptom-survey/end-of-survey.md

@@ -7,11 +7,11 @@ nav_order: 10
 # End of CTIS Data Collection
 {: .no_toc}
 
-The US COVID-19 Trends and Impact Survey will stop inviting new respondents to
+The US COVID-19 Trends and Impact Survey stopped inviting new respondents to
 complete the survey on June 25, 2022. All aggregate data will remain publicly
 available, and microdata will continue to be available to academic and nonprofit
-researchers. We provide details below on this decision and how it will affect
-users of the data.
+researchers. Below is the information we provided users of the data as the
+we prepared to end the survey.
 
 
 ## Why CTIS Data Collection is Concluding

docs/symptom-survey/index.md

@@ -13,19 +13,23 @@ social distancing), mental health, and economic and health impacts they have
 experienced as a result of the pandemic. A high-level overview of the survey is
 posted [on the COVIDcast website](https://delphi.cmu.edu/covid19/ctis/), and an
 international version is [conducted by the University of
-Maryland](https://covidmap.umd.edu/). Data collection [will cease on June 25, 2022](end-of-survey.md).
+Maryland](https://covidmap.umd.edu/). Data collection [ceased on June 25,
+2022](end-of-survey.md).
 
 The [survey results dashboard](https://delphi.cmu.edu/covidcast/survey-results/)
 provides a high-level summary of survey results. Geographically aggregated data
 from this survey is publicly available through the [COVIDcast API](../api/covidcast.md)
 as the [`fb-survey` data source](../api/covidcast-signals/fb-survey.md). Demographic breakdowns of survey
 data are publicly available as [downloadable contingency tables](contingency-tables.md).
 
-This documentation describes the survey items, data coding, data distribution,
-and the survey weights computed by Facebook. It also documents the individual
-response data, which is available to researchers with a signed Data Use
-Agreement. If you are a researcher and would like to get access to the data, see
-our page on getting [data access](data-access.md).
+The [CTIS Methodology
+Report](https://dataforgood.facebook.com/dfg/resources/CTIS-methodology-report)
+describes the survey design, data collection process, weighting, and aggregation
+processes, and is the primary reference for researchers working with the survey
+data. This website describes details specific to the US version of the survey
+and documents the individual response data, which is available to researchers
+with a signed Data Use Agreement. If you are a researcher and would like to get
+access to the data, see our page on getting [data access](data-access.md).
 
 If you have questions about the survey or getting access to data, contact us at
 <[email protected]>.
@@ -37,7 +41,7 @@ Group](https://delphi.cmu.edu/) at Carnegie Mellon University. Team members
 include:
 
 * [Alex Reinhart](https://www.refsmmat.com/), Principal Investigator
-* Wichada La Motte-Kerr, Survey Coordinator
+* Wichada La Motte-Kerr, Survey Coordinator (2020-2022)
 * Robin Mejia, survey advisor
 * Nat DeFries, statistical developer and data engineer
 * Eu Jing Chua (2020-2021) and Mashrin Srivastava (2021-2022), data analysis