The qubit $a\left|0\right>+b\left|1\right>$ is a superposition w.r.t. the basis $\left\lbrace\left|0\right>,\, \left|1\right>\right\rbrace$ because it may collapse to $\left|0\right>$ or $\left|1\right>$ when measured w.r.t. the above basis. However the same qubit, when measured w.r.t the basis $\left\lbrace a\left|0\right>+b\left|1\right>, b^*\left|0\right>−a^*\left|1\right>\right\rbrace$, always collapses to the first vector.
Can I therefore conclude that superposition is a basis-dependent concept?