About the Search String

The golden rule to design a good search string is to separate the keywords and synonyms with the boolean operator OR and separate the population, intervention, comparison and outcomes with parentheses and using the boolean operator AND, as following:

(population   OR synonym-1 OR synonym-2 OR synonym-n) AND
(intervention OR synonym-1 OR synonym-2 OR synonym-n) AND
(comparison   OR synonym-1 OR synonym-2 OR synonym-n) AND
(outcomes     OR synonym-1 OR synonym-2 OR synonym-n)

Good example

(software OR application OR product OR Web OR WWW OR project) AND (development OR "cross company" OR "cross organisation" OR "cross organization" OR multiple-organizational) AND ("multiple-organisational model" OR within-organisation OR within-organization OR within-organizational OR within-organisational OR "single company") AND (Accuracy OR "Mean Magnitude" OR "Relative Error")

Bad example

software or application or product or Web or WWW or project and development or cross company or cross organisation or cross organization or multiple-organizational and multiple-organisational model or within-organisation or within-organization or within-organizational or within-organisational or single company and Accuracy or Mean Magnitude or Relative Error