For example, although dress size is not a standard base for segmenting a market, some fashion houses have successfully segmented the market using women's dress size as a variable. However, the most common bases for segmenting consumer markets include: geographics, demographics, psychographics, and behaviour. Marketers normally select a single base for the segmentation analysis, although, some bases can be combined into a single segmentation with care. For example, geographics and demographics are often combined, but other bases are rarely combined. Given that psychographics includes demographic variables such as age, gender, and income as well as attitudinal and behavioural variables, it makes little logical sense to combine psychographics with demographics or other bases. Any attempt to use combined bases needs careful consideration and a logical foundation.