Visit local archives and websites such as www.headington.org.ukhistoryindex.htm and study photos of shops and high streets at different times.
Use extracts from programmes like Are You Being Served? or movies such as Brief Encounter (where the lady does the shopping) and compare this with more up to date views of shopping.
Look at the changes in an institution, such as the Co-op. Most local archives will have records on these stores.
Use this article as an entry point to some big issues. With the Depression, examine how the department store reflected the gap between rich and poor.
In Nazi Germany, the fate of stores owned by Jews is a grim but important story. Much Nazi propaganda aimed at the alleged dishonest activities of Jews can be found at the German Propaganda Archive (www.calvin.eduacademiccasgpa). Such material needs to be used with care, however (many other websites contain anti-Jewish propaganda, despite disclaimers).