Both "PhD" and "Ph.D." are correct; the choice depends on style preferences and current trends.
According to current trends, omitting periods in abbreviations for academic degrees is increasingly common. Thus, "PhD" is frequently seen in contemporary writing (Reference: 15-Sept-2023).
Here's a summary:
| Abbreviation | Periods | Correctness | Trend |
|---|---|---|---|
| PhD | No | Correct | Modern, Common |
| Ph.D. | Yes | Correct | Less Common |
Therefore, while both are acceptable, "PhD" is the more modern and frequently used form.
