Perceptual mapping is used to establish a product's or a brand's position and can provide a comprehensive picture of the competitive situation and how differentiated the product or brand is in the minds of the established target group. A perceptual map is a type of diagram, where the two axes depict the criteria, and their relative importance, the target group uses when selecting a product or brand to satisfy a certain need. Several maps must be drawn to get a full picture of how a certain product or brand is positioned. Any position is to be established in relation to any competitor, direct or one providing substitutes, satisfying the same need for the established target group. Market research (or otherwise obtained equal data) is required to find out the selection criteria – and their relative importance – of the target group. The position in perceptual maps is a relative one. To judge a position, the market share size for each competing product or brand should be included in the map. A product or brand with a small market share in the close proximity of a product or brand with a large market share should consider repositioning.