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GSS > Guidance > Methodology


The Government Statistical Service (GSS) works to ensure the methods used to produce government statistics are of a high standard.

What support is available?

Anyone in the GSS can access free methodological advice covering a wide range of topic areas.

Find out more about the methodological advice available to the GSS.

The annual GSS Methodology Symposium is an opportunity for members of the GSS to come together to network, share expertise and discuss important topics.

Take a look at papers and presentations from past GSS Methodology Symposiums

Keep an eye on the events page for information about the next symposium.


Support by topic

What is data linking?

The government holds an enormous amount of data.  By using it effectively, we provide insight, drive policy change and answer society’s most important questions.  While datasets are useful on their own, bringing them together means that we can take advantage of the combined resource they offer.

Data linking is the process of joining datasets together so that we can make as much use as possible of the information they hold.


Data linking 


Introduction to data linking

What are SOC codes?

Standard Occupational Classification (SOC) codes are a coding system used to classify occupations, enabling comparisons of occupations across different datasets.

The Office for National Statistics (ONS) is responsible for maintaining and updating the SOC codes. The SOC codes were introduced in 1990, with a major revision in 2000 and a minor revision in 2010.


Find out more about SOC2010 and the National Statistics Socio-economic Classification (NS-SEC).


Contact the groups that deal with SOC revisions and extensions.

What is statistical disclosure control?

Statistical Disclosure Control (SDC) is the term used to cover the many methods of safeguarding the confidentiality of the information held by the GSS about individuals and businesses.

Information obtained from surveys or administrative data is usually given in confidence. SDC is applied to ensure that individuals, businesses or other statistical units cannot be identified from published data.

Recent technological advances, along with the requirement for open data, have dramatically increased the volume of data available. These advances have given the issue of disclosure control greater importance.

SDC involves modifying data so that the risk of identification is reduced to an acceptable level. At a basic level, this involves reducing detail (recoding variables) or damaging the data (perturbing values). Disclosure control methods aim for a balance between the improvement in confidentiality protection and the reduction in data quality.

Generally, rare combinations of attributes lead to the identification of individuals, for example, a sixteen-year-old widow or a single manufacturer in an area. Disclosure control methods are usually applied if ethical, practical or legal considerations require the data to be protected, and the possibility of identification exists.


Disclosure control for tables produced from administrative sources

Disclosure control for tables produced from surveys

Disclosure control for microdata produced from social surveys


Introduction to statistical disclosure control


Email to ask for advice on SDC.

What is time series analysis?

The data we work with often comes in the form of a time series, i.e. a series of data points representing values at different points in time. This section provides links to the time series analysis help available to the GSS.




View information from past workshops for international time series experts.

Keep an eye on the events page for upcoming events related to time series.


The Time Series Analysis Branch (TSAB) at the Office for National Statistics (ONS) provides expertise in time series analysis, in particular seasonal adjustment.

TSAB is responsible for the quality of all ONS seasonal adjustment and manages a rolling programme of annual seasonal adjustment reviews of statistical outputs across ONS.

TSAB also provides support and training for practitioners and users of seasonal adjustment across the GSS. It is the main point of contact for any questions or queries regarding seasonal adjustment and time series analysis in official statistics.


Statisticians and data scientists are required to use many different statistical computer programs. This section contains links to some of the help available to the GSS.


There are many websites that can offer help with statistical computer programs

For example:


The Learning Academy and the Data Science Campus organise and provide training in using statistical computer programs:


Join the slack workspace for government data science.

Email or tweet the data science campus:

Twitter: @DataSciCampus