Published online by Cambridge University Press: 20 November 2018
The Banach spaces   $L(X,Y),K(X,Y),{{L}_{{{w}^{*}}}}({{X}^{*}},Y)$ , and
 $L(X,Y),K(X,Y),{{L}_{{{w}^{*}}}}({{X}^{*}},Y)$ , and   ${{K}_{{{w}^{*}}}}({{X}^{*}},Y)$  are studied to determine when they contain the classical Banach spaces
 ${{K}_{{{w}^{*}}}}({{X}^{*}},Y)$  are studied to determine when they contain the classical Banach spaces   ${{c}_{o}}$  or
 ${{c}_{o}}$  or   ${{l}_{\infty }}$ . The complementation of the Banach space
 ${{l}_{\infty }}$ . The complementation of the Banach space   $K(X,Y)$  in
 $K(X,Y)$  in   $L(X,Y)$  is discussed as well as what impact this complementation has on the embedding of
 $L(X,Y)$  is discussed as well as what impact this complementation has on the embedding of   ${{c}_{o}}$  or
 ${{c}_{o}}$  or   ${{l}_{\infty }}$  in
 ${{l}_{\infty }}$  in   $K(X,Y)$  or
 $K(X,Y)$  or   $L(X,Y)$ . Results of Kalton, Feder, and Emmanuele concerning the complementation of
 $L(X,Y)$ . Results of Kalton, Feder, and Emmanuele concerning the complementation of   $K(X,Y)$  in
 $K(X,Y)$  in   $L(X,Y)$  are generalized. Results concerning the complementation of the Banach space
 $L(X,Y)$  are generalized. Results concerning the complementation of the Banach space   ${{K}_{{{w}^{*}}}}({{X}^{*}},Y)$  in
 ${{K}_{{{w}^{*}}}}({{X}^{*}},Y)$  in   ${{L}_{{{w}^{*}}}}({{X}^{*}},Y)$  are also explored as well as how that complementation affects the embedding of
 ${{L}_{{{w}^{*}}}}({{X}^{*}},Y)$  are also explored as well as how that complementation affects the embedding of   ${{c}_{o}}$  or
 ${{c}_{o}}$  or   ${{l}_{\infty }}$  in
 ${{l}_{\infty }}$  in   ${{K}_{{{w}^{*}}}}({{X}^{*}},Y)$  or
 ${{K}_{{{w}^{*}}}}({{X}^{*}},Y)$  or   ${{L}_{{{w}^{*}}}}({{X}^{*}},Y)$ . The
 ${{L}_{{{w}^{*}}}}({{X}^{*}},Y)$ . The   ${{l}_{p}}$  spaces for
 ${{l}_{p}}$  spaces for   $1\,=\,p\,<\,\infty $  are studied to determine when the space of compact operators from one
 $1\,=\,p\,<\,\infty $  are studied to determine when the space of compact operators from one   ${{l}_{p}}$  space to another contains
 ${{l}_{p}}$  space to another contains   ${{c}_{o}}$ . The paper contains a new result which classifies these spaces of operators. A new result using vector measures is given to provide more efficient proofs of theorems by Kalton, Feder, Emmanuele, Emmanuele and John, and Bator and Lewis.
 ${{c}_{o}}$ . The paper contains a new result which classifies these spaces of operators. A new result using vector measures is given to provide more efficient proofs of theorems by Kalton, Feder, Emmanuele, Emmanuele and John, and Bator and Lewis.