Thermatic Maps

Thematic Maps emphaise the spatial distrubution of a variable over space. Thematic Maps can help show the difference in a variable, say age, between two or more states/counties/cities. http://images.google.com/imgres?imgurl=http://www.lib.wsc.ma.edu/themap.jpg&imgrefurl=http://www.lib.wsc.ma.edu/censusaff.htm&h=381&w=505&sz=36&hl=en&start=2&sig2=YtY_7GVPhsWD8BJTblpf2Q&um=1&tbnid=lfQhH-KYeLkvyM:&tbnh=98&tbnw=130&ei=cLmbSP2IB5ewiwHNkPzmBQ&prev=/images%3Fq%3Dthematic%2Bmap%26um%3D1%26hl%3Den%26safe%3Doff%26rlz%3D1T4GFRC_en___US219%26sa%3DN