I worry that this valuable classroom practice will be lost in a fast-paced educational environment that values quantitative data (and its technical adequacy).
Conferring will not result in a numerical score. It probably isn't reliable or valid. But, within about 60-seconds a conference can tell a teacher a whole lot about what a student knows and doesn't know quite yet while building a relationship with the student.
Conferring is a valuable tool for formative assessment.
The following resources provide some further information.
Resource 1: Conferring General Information
This resource provides curated information about conferring, including how it fits within a gradual release of responsibility instructional framework. It is part of a larger resource from the Department of Public Instruction about about instruction in English language arts.
(Select "Independent Task" and "Conferring")
RESOURCE 2: Conferring How-To
The above document is part of a Classroom Strategies and Practices bank hosted at the Wisconsin RtI Center. It provides step-by-step directions and supporting record keeping forms.
The bank includes other assessment strategies and practices. (In addition, the bank includes instructional strategies and practices for each cluster within the CCSS ELA standards for reading literature and informational texts.
Resource 3: Conferring via GoogleHangouts
This great blog post (from Two Writing Teachers) describes one teacher's experimentation with GoogleHangouts as a place to host writing conferences.