The phrase "a direct observer" is correct and usable in written English.
It can be used to refer to someone who witnesses an event or phenomenon firsthand, without any intermediaries.
Example: "As a direct observer of the experiment, I can attest to the accuracy of the results."
Alternatives: "an eyewitness" or "a firsthand witness".
The goal is to assign numbers to perceptual events, the benefit of which is that it allows for direct observer response to changes, although restricted to only a number of categories [23].
In addition to sampling from two geographic areas of different composite SES (below), we included direct observer ratings of neighborhoods.
This study investigated if video-based assessment was a reliable tool for cystoscopy and if direct observers were prone to bias compared with video-raters.
Furthermore, disagreements on the mechanisms are not only found between the reports of direct observers but also in the analyses of scholars.
However, this has long been a challenging endeavour, as insurgency imposes specific limitations on the data that could speak to these interactions: quantitative data is limited by the difficulties of systematic collection in war, while qualitative data may include vague or conflicting insights from direct observers.
In contrast to other studies, there were no direct observers.
Nurses are on the frontline of patient care and are direct observers of pain behaviors and therapeutic responses; nurses are therefore key stakeholders in promoting safe comfortable care.
The light source used for producing values of room lighting and background luminance was placed, hidden, at the end of the room, thus avoiding a direct projection on the observer and unwanted reflections on the observer's vision.
The analysis of hits and the false alarms suggests that observing painful grasps has a direct effect on the observers' own tactile processes.
