3.2 Text/ Html

Different data formats use different binary encodings as an agreed method of interpreting sequences of binary numbers. For example, the American National Standards Institute (ANSI) developed an encoding for alphanumeric characters known as the American Standard Code for Information Interchange or ASCII. ASCII can be used to translate between seven digit binary sequences and alphanumeric characters. It is a format which is familiar to me in my profession as a GIS analyst via the ESRI ASCII Raster format which we use to store digital elevation models.


Different data formats allow computers to use binary code to represent data in different ways to support a range of uses and activities. For example, in GIS the .shp file format is used to store spatial information relating to a vector data type and .prj is used to store information about the geographic projection system. Most data types are proprietary so knowing which program should be used to view a particular data type is key. If I open an ESRI .shp file in Microsoft word, for example, the result is useless (see image). Different data formats require a particular program to allow the file to be read correctly and so enable the user to extract meaning from it.


So data formats allow us to extract meaning from different types of data by interpreting sequences of binary in different ways. Metadata and markup allow us to impart even more meaning to data essentially by providing data about data. For example, in a word (.doc) document, metadata might be used to denote the font type, size and colour. In GIS metadata is normally stored and displayed as an xml file. It is described in an Esri Whitepaper as "a summary document providing content, quality, type, creation and spatial information about a dataset".