a mixed bag of vs heterogeneous

a mixed bag of

heterogeneous

adj
  • Incommensurable because of different kinds. 

  • Diverse in kind or nature; composed of diverse parts. 

  • Visibly consisting of different components. 

  • Of a network comprising different types of computers, potentially with vastly differing memory sizes, processing power and even basic underlying architecture; alternatively, of a data resource with multiple types of formats. 

  • Having more than one phase (solid, liquid, gas) present in a system or process. 

How often have the words a mixed bag of and heterogeneous occurred in a corpus of books? (source: Google Ngram Viewer )