Insight SEN2 Data Suppression

Overview

Due to the nature of SEN2 data, data suppression is required everywhere the SEN2 data appears across Nexus. NCER is responsible for ensuring that all data and analysis in Nexus are presented appropriately and reducing the risks of users misusing the analysis, even by accident. This is done with the use of small-number rounding, suppression and secondary suppression.

Please note that SEN2 NPD data is not currently available in Nexus, but NCER is working with DfE to make this available in the 2024/25 academic year. When NPD is available, there are strict guidelines on data rounding and suppression that NCER and Nexus users must follow to ensure the data and analyses are only used as the DfE has given permission for. As these guidelines reflect best practices, the NCER has applied the same rules specified by the DfE for CiN data across all SEN2 data sources.

For full details of the Nexus terms and conditions of use, including NPD data, please follow this link.

NCER encourages local authorities to import their SEN2 data, not only to benefit from the range of analyses available on the cohort page and the data matched within the Keypas grids but also from the early indicative national figures. The more LAs import their data, the more accurate the national figures will be. This early analysis aims to support effective interventions at the earliest opportunity for some of the most vulnerable pupils nationally. Please note this data should not be published in any way, including usage in documents that will be publicly available (such as scrutiny reports).

SEN2 Data Rounding and Suppression Rules

The following data suppression rules are applied to all SEN2 data:

• If a child is educated in a different LA to the LA that holds the EHCP, the child's school data will not be available to the LA holding the EHCP (or assessment, etc.) in child-level analysis or any Keypas or Insight data exports.
• If one number is suppressed, at least one other number must be suppressed (the next smallest) to avoid the calculation of suppressed values from the totals.
• Any outputs including SEN2 (or SEN2 matched with NPD, such as school census) counts between 1 and 5 inclusive must be suppressed.
• National and regional counts should be rounded to the nearest 10.
• Percentages where the numerator is between 1 and 5 inclusive or where the denominator is between 1 and 10 inclusive must be suppressed.
• For SEN2 data, zero is allowed. For SEN2 matched with NPD data, zero is not allowed for attainment data and should be suppressed.

• SEN2 percentages should be rounded to one decimal place. For SEN2 data matched with NPD – it is rounded to the same number of decimal places as in the national publications for each outcome (for example, most KS4 data is rounded to 1dp).

• Calculated figures such as percentages or averages that would round to zero (e.g. less than 0.05%) but are not zero will be suppressed.
• SEN2 data at the individual school level should not be published including usage in documents that will be publicly available (such as scrutiny reports).
• No suppression or rounding is required on any pupil, school, virtual school or local authority-based figures within a local authority's/virtual school's domain. In other words, rounding and suppression have been applied to Nexus SEN2 data where the analysis at school, regional or national level includes data from SEN2 children educated in another LA.