"10-Minute Inbox Zero" Validation Protocol
Validate the claim that users can achieve inbox zero for 10,000+ emails within 10 minutes using Emailibrium (docs/plan/inception.md Section 2.2, docs/research/initial.md Section 6.4).
N >= 30 heavy email users (>100 emails/day)
Recruited from tech professionals (mix of roles: engineering, product, support, sales)
Must have at least one email account with 5,000+ emails in the inbox
Exclusion criteria: prior experience with vector-based email tools, email bankruptcy practitioners
Average daily email volume
Current time spent managing email (minutes/day)
Number of unread emails in primary inbox
Email clients used (Gmail web, Outlook, Apple Mail, etc.)
Self-rated email management skill (1-5 Likert scale)
Phase 0: Setup (not timed)
Participant signs informed consent
Research assistant verifies inbox size >= 5,000 emails
System requirements check (browser version, network speed)
Phase 1: Baseline Measurement (5 min)
Participant attempts to organize inbox using their current email client
Record: number of emails triaged, actions taken, strategy used
Timer stops at 5 minutes
Capture screenshot of inbox state
Phase 2: Connection (2 min)
Connect email account to Emailibrium via OAuth
Verify successful connection
Note any connection issues
Phase 3: Ingestion (measured, not counted in triage time)
System processes all emails
Record: total ingestion time, emails/second throughput
Record: time to first usable result (streaming threshold)
Record: peak memory usage during ingestion
Phase 4: Triage (timed -- primary metric)
Participant uses Inbox Cleaner to reach inbox zero
Timer starts when participant clicks "Start Analysis"
Timer stops when last action is taken (inbox empty or all items triaged)
Record: every click/tap via event tracking
Record: which features were used (batch actions, categories, search)
Phase 5: Satisfaction Survey
System Usability Scale (SUS) -- standard 10-item questionnaire
Custom questions (see below)
Open-ended feedback
#
Question
Scale
Q1
I felt confident in the system's email categorization
1-5 Likert
Q2
The batch actions saved me significant time
1-5 Likert
Q3
I would trust this system with my daily email management
1-5 Likert
Q4
The semantic search found emails I could not find before
1-5 Likert
Q5
I would recommend this tool to a colleague
1-5 Likert
Measure inbox rebound: how many emails accumulated without being triaged
Repeat SUS questionnaire
Record: daily usage time, features used
Metric
Target
How Measured
Time to inbox zero
< 10 min
Stopwatch from "Start Analysis" to last action
User actions required
< 50
Click/tap count via event tracking
Ingestion throughput
> 500 emails/sec
Server metrics (emails processed / elapsed time)
User satisfaction
SUS > 70
Post-task questionnaire
1-week inbox rebound
< 100 emails
Follow-up measurement
Categorization accuracy
> 95%
Manual spot-check of 20 random emails per participant
Search latency (p95)
< 50ms
Server-side instrumentation
Error rate
< 1%
Count of failed actions / total actions
Condition A: Current Email Client (within-subjects)
Same participant, same inbox, existing email client
5-minute timed triage session
Measures baseline organizational speed
Order counterbalanced: half of participants do Condition A first
Condition B: Emailibrium Without Vector Intelligence
Emailibrium UI with keyword search only (vector features disabled)
Same triage task as the experimental condition
Isolates the value added by semantic/vector intelligence
Useful for attributing improvement to vector tech vs. better UI
Condition C: Full Emailibrium (experimental)
All features enabled: semantic search, vector classification, batch actions, insights
Primary experimental condition
Paired t-test (or Wilcoxon signed-rank if normality violated) for time comparison between conditions
Effect size: Cohen's d
Minimum detectable effect: 5 minutes (half the target)
Alpha: 0.05, Power: 0.80
Required sample size: N >= 27 (computed via G*Power for paired t-test with d=0.5); N=30 accounts for dropout
ANOVA across all three conditions with Bonferroni correction
Regression: time-to-inbox-zero ~ inbox_size + daily_volume + self_rated_skill
Correlation: SUS score vs. time-to-inbox-zero
Sub-group analysis: heavy users (>200 emails/day) vs. moderate users
Inter-rater reliability for manual categorization accuracy check (Cohen's kappa)
Outlier detection: participants who did not follow instructions (e.g., deleted all emails without reading)
Missing data handling: last observation carried forward for dropout participants
Informed consent required before participation
Email data processed locally only -- never transmitted to research servers
Participants can withdraw at any time without penalty
No email content shared with researchers; only aggregate metrics collected
Study protocol reviewed by institutional ethics board (or equivalent)
Data retention: anonymized metrics kept for 2 years; raw logs deleted after analysis
Compensation: participants receive a summary of their inbox health report
Dedicated test server with reproducible configuration
Network latency monitoring throughout sessions
Browser: latest Chrome or Firefox (controlled variable)
Minimum hardware: 8GB RAM, modern multi-core CPU
Frontend event tracking: all clicks, keypresses, navigation events
Backend metrics: API latency, throughput, error rates
System metrics: CPU, memory, disk I/O during ingestion
All timestamps synchronized via NTP
All metrics stored in a separate analytics database (not the production email database)
Participant IDs are pseudonymized (UUID, no PII in analytics)
Raw event logs encrypted at rest
Statistical report with primary and secondary analysis results
Participant experience summary (anonymized quotes, common themes)
Technical performance report (throughput, latency percentiles)
Recommendations for product improvement based on observed pain points
Internal report: within 2 weeks of study completion
Blog post: anonymized summary of key findings
Academic paper (optional): if results are statistically significant and novel