A web platform for publishing data. The aim of a data portal is to provide a data catalogue, making data not only available but discoverable for data users, while offering a convenient publishing workflow for publishing organisations.

Breaking a data block into smaller chunks by following a set of rules so that it can be more easily interpreted, managed or transmitted by a computer.

The practice of examining large pre-existing databases in order to generate new information. ‘For example, one Midwest grocery chain used the data mining capacity of Oracle software to analyse local buying patterns. They discovered that when men bought diapers on Thursdays and Saturdays, they also tended to buy beer. Further analysis showed that these shoppers typically did their weekly grocery shopping on Saturdays. On Thursdays, however, they only bought a few items.

The policies, procedures, and technical choices used to handle data through its entire lifecycle from data collection to storage, preservation and use. A data management policy should take account of the needs of data quality, availability, data protection, data preservation, etc.

If personal data has been imperfectly anonymised, it may be possible by piecing it together (perhaps with data available from other sources) to reconstruct the identity of some data subjects together with personal data about them. The personal data, which should not have been published (see data protection), may be said to have ‘leaked’ from the ‘anonymised’ data. Other kinds of confidential data can also be subject to leakage by, for example, poor data security measures.

The ability to work with data is an increasingly important part of a journalist’s armoury.

Almost any interesting use of data will combine data from different sources. To do this it is necessary to ensure that the different datasets are compatible: they must use the same names for the same objects, the same units or co-ordinates, etc. If the data quality is good this process of data integration may be straightforward but if not it is likely to be arduous.

A large amount of data transferred from one system or location to another.

Source: EU OD

A crawler is a programme that visits web sites and reads their pages and other information in order to create entries for a search engine index. The major search engines on the web all have such a programme, which is also known as a ‘spider’ or a ‘bot’.

Datasets are created by collecting data in different ways: from manual or automatic measurements (e.g. weather data), surveys (census data), records of decisions (budget data) or ongoing transactions (spending data), aggregation of many records (crime data), mathematical modelling (population projections), etc.