The 1/d expansion method for polymer chains is examined by comparing these expansions for several thermodynamic and structural quantities with the results of standard series analysis of exact enumeration data. The comparisons cover a wide range of spatial dimensions d, including non-integer ones, and are performed for particular values of interaction energy. Good agreement is generally found for d>4, whereas discrepancies become conspicuous as d decreases to d=2. Reasonable values are obtained for the exponents v and gamma in d=2-4 by applying the coherent-anomaly method of Suzuki (1986) to our 1/d expansions through fifth order in d^-1.