These fields frequently overlap but tend to use different methodologies and techniques. This can be accomplished by use of development methodologies and good implementation techniques. Lean management and Six Sigma are two concepts which share similar methodologies and tools. Numerous threat modeling methodologies are available for implementation. It entails numerous forms of research which employ different methodologies. SDLC can be described along a spectrum of agile to iterative to sequential methodologies. It is also developed using system programming methodologies and systems programming languages. The twentieth century saw improvements to the quantitative methodologies employed in sociology. Due to the different methodologies and definitions used different sources often provide significantly different data. Accelerated feature delivery is further enabled by agile software development methodologies. Many different methodologies are used to study cognitive science. To Geertz, analysis separated observation from interpretative methodologies. These steps are often overseen by a project manager using project management methodologies. Different samples, methodologies, and screening instruments are employed across studies. Several varieties have been developed applying conventional breeding methodologies.