Abstract
Research has shown the strong association between therapeutic alliance and therapeutic outcomes. A good alliance is linked with better outcomes in psychotherapy. A number of instruments have been developed to measure the alliance aimed at therapists, patients, and observers. Observational instruments are less intrusive, and reduce the possible effects that measurements may have on treatment. In addition, they have proven to be more valid in some clinical populations. In Chile, there are no reliable and validated instruments to measure the therapeutic alliance from the point of view of an observer. The present article introduces a translation into Spanish along with an adaptation and validation for Chile of the Work Alliance Inventory (WAI-O) in its observational version. WAI-O is a valid and reliable instrument for measuring the therapeutic alliance.
