Personally, the topic says that two people randomly choose one of the three stations, so they have the opportunity to choose the same station for investigation.

Replace Xiao Wang and Xiao Lin with A and B. A chooses A as 1/3, and B chooses B different from A and adjacent to A as 1/3. Multiply them to get1/9-(1); If A chooses B 1/3, then A and C different from A are 2/3, which are multiplied by 2/9-(2); A chooses C as 1/3, and B chooses B different from A but adjacent to A as 1/3, and the two are multiplied by1/9-(3); ( 1)+(2)+(3)=4/9